mm-112 ?6hlistrecoHptxelongfnt#shorfontTEXTGenevaptszfixd8listrecopjstenumleft(FISH ÊGeneva??. 7?1.01.01.01.0???????6!{?Ec frWEst~WEpf?ru?P¢stylnüISH?TABS?WDTH¸jstf?rct?lct?PRopB Kco[YAcute]?&??[YAcute]?&?cú??x&?,[YAcute]???h[YAcute]?[CapitalA Grave]&?1Ú2[YAcute]??&?[YAcute]?????? !?8[YAcute]?!?@[YAcute]?!?P[YAcute]?!?ø[YAcute]?&!?[YAcute]?2!? D[YAcute]?x!??1/2(p^2 + 1) is odd and 1/2(p^2 + 1) + p is even.That means we have a guaranteed factoring (f1, f2) where f1 - f2 iseven and we get a maximum for a_(p+1): a_p(+1) <= (1/2(p^2 + 1) + p - 2) / 2 = 1/4 p^2 + 1/2 p - 3/4 <= 1/2 p^2 - 1/2 = a_p, since 1/2 p^2 - 1/2 1/4 p^2 + 1/2 p - 3/4 < 2p^2 - 2 p^2 + 2p - 3 < p^2 - 2p + 1 0 < (p - 1)^2 0which completes the proof. My initial question has had to run the gauntlet and> did not come out unscathed (i.e., as a tough question... it> turned out to be really easy). But, perhaps, theres still> a little life left in it, afterall?> > My Guess is as Good as Yours Theorem 1.2:> Let (G,*) be a (nite) non-abelian group with nontrivial> center and assume it possible tofind a ring (R, *, +)> such that G is a subgroup of R with respect to *. In> addition, assume that for all x in G: -x(R) in G (where> -x(R) is dened as the additive inverse of x). Then G> is of even order.G any nite group. R = F_2 G, the group ring of G over theeld F_2 of two elements. G embeds obviously in R^* andas R has characteristic 2, then -x = x for all x in G.Of course, G can have odd order, and nontrivial centre.-- Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.htmlNeedless to say, I had the last laugh. Alan Partridge, _Bouncing Back_ (14 times) =The Klein bottle is a 2-dimensional non-orientable surface.Is there a 3D manifold analog?Are 3D non-orientable manifolds excluded from the 3-manifoldclassication program (as in Thurstons Geometrization Conjecture) ?David Bernier =|The Klein bottle is a 2-dimensional non-orientable surface.||Is there a 3D manifold analog?I think of the Klein bottle as a cylinder S^1 x [0,1], withthe ends S^1x{0} and S^1x{1} identied with each otherby an orientation-reversing mapping. That is, if S^1 isthe unit circle {(x,y)|x^2+y^2=1}, then we identify((x,y),0) with ((-x,y),1) or something like that.The easiest analog I can think of is to take a cylinderS^2x[0,1] and identify the ends S^2x{0} and S^2x{1}by an orientation-reversing mapping... a case of whatLee Rudolph mentioned as an S^2 bundle over S^1(where [0,1] with {0} and {1} identied is the base S^1).Keith Ramsay The Klein bottle is a 2-dimensional non-orientable surface.Is there a 3D manifold analog?What do you want analog to mean here? Certainly there are plenty of 3-dimensional non-orientable manifolds. The Kleinbottle K is an S^1-bundle over S^1; there are 3-dimensionalnon-orientable manifolds which are M-bundles over N,for (M,N) any of (S^1 x S^1, S^1), (K, S^1), (S^1, S^1 x S^1),(S^1, K), (S^1, S^2), (S^2, S^1), and those are all analogsof K in some sense. >Are 3D non-orientable manifolds excluded from the 3-manifold>classication program (as in Thurstons Geometrization Conjecture) ?Nope, theyre included too (for an appropriate formulation ofthe conjecture).Lee Rudolph >The Klein bottle is a 2-dimensional non-orientable surface.Is there a 3D manifold analog?> > What do you want analog to mean here? Certainly there are > plenty of 3-dimensional non-orientable manifolds. The Klein> bottle K is an S^1-bundle over S^1; there are 3-dimensional> non-orientable manifolds which are M-bundles over N,> for (M,N) any of (S^1 x S^1, S^1), (K, S^1), (S^1, S^1 x S^1),> (S^1, K), (S^1, S^2), (S^2, S^1), and those are all analogs> of K in some sense. [...]I was thinking of a compact 3-manifold that can be obtainedthrough abstract gluing, as is explained on this Web pagefrom the Math. Dept. at Ohio State University:http://www.math.ohio-state.edu/~edorow/math655/ Klein2.htmlThe crab on the Klein bottle is pretty good.David Bernier >The Klein bottle is a 2-dimensional non-orientable surface.>>Is there a 3D manifold analog?and now explains:>I was thinking of a compact 3-manifold that can be obtained>through abstract gluing, as is explained on this Web page>from the Math. Dept. at Ohio State University:http://www.math.ohio-state.edu/~edorow/math655/ Klein2.html*Every* compact 3-manifold ... can be obtained through abstract gluing. In particular, among the examples I mentioned before,non-orientable M bundles over N, for (M,N) any of (S^1 x S^1, S^1), (K, S^1), (S^1, S^1 x S^1), or (S^1, K) (where K is the Kleinbottle, and of course S^1 is the circle, so S^1 x S^1 is the2-dimensional torus) can be obtained through abstract gluingof a 3-dimensional cube! Take Zbiggys crab-cage, pull it upinto the third dimension to make a cube, then glue the top ofthe cube (out in the room) to the bottom of the cube (back onyour screen), and glue the other four faces to each other in pairs following the gluing that makes the crab-cage into aKlein bottle; at this point you have a non-orientable compact3-manifold with some claim to being called a 3-dimensionalKlein bottle.For a different sort of example (different in that it isnta bundle), take a cube as before, and glue each face to itsopposite, with a 180-degree rotation. The resulting manifoldis the 3-dimensional real projective space. Again, its non-orientable.Lee Rudolph Im just a sophomore in college, so I dont know much. In our math> book, it said the integral of sin(x^2) cant be integrated easily. > What does it mean, easily? Is there a simple antiderivative of> sin(x^2), or is it some kind of innite thing? Has it been proven> either way? Im just curious...> > John SavageIt means there is no simple formula for that indenite integral.There is a technical notion of elementary function... algebraicfunctions, trig functions, inverse trig functions, exponentialfunctions, log functions, and nite combinations of these (includingby composition). It has been proved that there is no elementaryfunction with derivative equal to sin(x^2).Some other common ones are: exp(-x^2), exp(x)/x, sin(x)/x,sqrt(polynomial of degree >=3). *** Integration in Finite Terms ***This theory goes back to Liouville, 1835.Classic text on the subject: J. F. Ritt, _Integration in Finite Terms_ (Columbia Univ Pr, 1948)Introductory papers, aimed at undergraduates: A.D. Fitt & G.T.Q. Hoare, The closed-form integration of arbitrary functions. Mathematical Gazette (1993) 227--236. E. Marchisotto & G. Zakeri, An invitation to integration in nite terms. College Math. J. 25 (1994) 295--308. A modern text (omitting the algebraic case) M. Bronstein, _Symbolic Integration I: Transcendental Functions_ (Springer-Verlag 1997)-- G. A. Edgar http://www.math.ohio-state.edu/~edgar/ exp[y] means e^yMathematicians write exp(y), only Mathematicaicians write Exp[y]. denoncou@euclid.colorado.edu (Hugh>>I have been having some difculties with the following problem:It is from Royden (p127 #17). The space throughout is assumed to be[0,1], though I think any nite measure space will work. Suppose p > 1. Suppose f_n -> f a.e. , f is in L_p and f_n is inL_p for all n. Suppose there exists M such that || f_n || (p-norm) <= M for all n. Suppose g is in L_q. Show that g*f_n -> g*f in the L_1 norm. >>If epsilon > 0 then there exists delta > 0 such that if m(A) < delta>>then the L^q norm of g*chi_A is less than epsilon, because ___.>>Now there exists a set A of measure less than delta such that>>f_n -> f ___ly on the complement of A, by ___s theorem...>>[...]It is not mentioned here, but in the problem, is 1/p + 1/q <= 1 assumed?>If not, then g*f might not even be in L^1.Well of course. In careful writing one would certainly want to state1/p + 1/q = 1 explicitly, but in the present context, given that the OP clearly has some idea what hes talking about, thats very clearlyan implicit assumption.>[...]One must have p > 1. Thats correct. Luckily p > 1 _was_ given explicitly in the problem.>[...]************************David =So far Ive come to the conclusion that there is a largest topology thatassures the assigned limits. This again is with the new understandingthat the topology generated by a bunch of sets is the topology with thesubbase of those sets. So any topological property expressible solely withsubbase sets and set theory will be preserved upon union of topologieswith that property.Im still puzzle showing the product topology {0,1}^S or actually thepower-set topology is the largest topology assuring the assigned limits.Another puzzle Im musing upon is if a topology assuring the assignedlimits can be enlarged to a 1st countable topology while still assuringthe assigned limits. This I think likely not possible. [...]> > Im still puzzle showing the product topology {0,1}^S or actually the> power-set topology is the largest topology assuring the assigned limits.>You have shown that, in this topology, all the topological limits areset-limits, no? Something to ponder: If you start throwing in moreopen sets, do you lose some of these convergences? > Another puzzle Im musing upon is if a topology assuring the assigned> limits can be enlarged to a 1st countable topology while still assuring> the assigned limits. This I think likely not possible.Do you really mean enlarge? The coinduced topology is already thelargest. Also, it seems to me that to make a space rst countable,you have to *remove* open sets, not add them, no? (Not sure aboutthat one.) For example, all sequences converge to every point in theindiscrete topology, which is rst countable. Thus, you could use asa subbase the union of all rst countable topologies where thesequences converge to the designated limits. Trouble is, you get evenmore convergent sequences than before.SJH =Van Jacques> This is a reponse to a comment something like of what use is> abstract math.> Pure math is on the whole distinctly more useful that applied.> For what is useful above all is technique, and math technique> is taught mainly through pure math....Nowadays many sorts of mathematical and physical things are modelled interms of _sets_ of points. But where do you suppose the method was rstused? If I mistake not, it was in Dedekinds denition of an ideal number,as a kind of subset (a submodule) of the ring C. And what was the motive forbringing in ideals? Trying to prove FLT, of course!Dedekind cuts, dening a real number as a set of rationals, came later.LH =Van Jacques>> This is a reponse to a comment something like of what use is>> abstract math.>> Pure math is on the whole distinctly more useful that applied.>> For what is useful above all is technique, and math technique>> is taught mainly through pure math.>...>Nowadays many sorts of mathematical and physical things are modelled in>terms of _sets_ of points. But where do you suppose the method was rst>used? If I mistake not, it was in Dedekinds denition of an ideal number,>as a kind of subset (a submodule) of the ring C. And what was the motive for>bringing in ideals? Trying to prove FLT, of course!Not really. The reason for bringing in ideals was to present aconcrete counterpart to Kummers ideal numbers, which was subject togeneralization in arbitrary number elds (both Dedekind and Kroneckerhad run into trouble in trying to use Kummers approach in rings ontegers that did not have an integral basis made of powers of thesame element). And while Kummer used his approach to prove FLT forregular primes, he never considered it particularly important. It wasall an unintentional consequence of his ->true<- interest:generalising quadratic reciprocity to higher reciprocity laws.-- == ==Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) =Arturo Magidinmagidin@math.berkeley.edu* Van Jacques> Kronecker: God made integers, the rest is the work of man.This was said in anger when Cantor experienced with higherinnities. However, I often think it nowadays is used to indicatehow ingenious and wonderful the integers are. Gods invention wassimple and great, and he left us all to investigate and discover allthe beautiful properties that can be found in the realm of numbers.I believe.-- Jon Haugsand > Number of positions...> After exactly two pawn moves:> ... after two moves by the same pawn: 16> ... after two pawns each moving 1 step: 28> ... after two pawns each moving 2 steps: 28> ... after two pawns, one moving 1 and one moving 2: 56> TOTAL: 128> > After a pawn move and a non-pawn move:> ... after a3: 4> ... after a4: 6> ... after b3: 6> ... after b4: 6> ... after c3: 6> ... after c4: 7> ... after d3: 12> ... after d4: 13> ... after e3: 15> ... after e4: 15> ... after f3: 4> ... after f4: 5> ... after g3: 6> ... after g4: 6> ... after h3: 4> ... after h4: 6> TOTAL: 121> > After a knight move and a rook move: 4> After two moves by same knight: 11> After two moves by different knights: 4> TOTAL: 19> > Grand total: 128+121+19=268But i don`t really understand it!the 16 is ok, but how do you get the 28?I think after the two moves of the pawn you go backto the initial boardposition, right? How do i get upto 28 different positions by moving 2 pawns, each one step?complicated stuff...:-( > Number of positions...> After exactly two pawn moves:> ... after two moves by the same pawn: 16> ... after two pawns each moving 1 step: 28> ... after two pawns each moving 2 steps: 28> ... after two pawns, one moving 1 and one moving 2: 56> TOTAL: 128> > > After a pawn move and a non-pawn move:> ... after a3: 4> ... after a4: 6> ... after b3: 6> ... after b4: 6> ... after c3: 6> ... after c4: 7> ... after d3: 12> ... after d4: 13> ... after e3: 15> ... after e4: 15> ... after f3: 4> ... after f4: 5> ... after g3: 6> ... after g4: 6> ... after h3: 4> ... after h4: 6> TOTAL: 121> > After a knight move and a rook move: 4> After two moves by same knight: 11> After two moves by different knights: 4> TOTAL: 19> > Grand total: 128+121+19=268> > But i don`t really understand it!> the 16 is ok, but how do you get the 28?> I think after the two moves of the pawn you go back> to the initial boardposition, right? How do i get up> to 28 different positions by moving 2 pawns, each one step?> > complicated stuff...:-(28 is found by what mathematicians call 8 choose 2. Look upcombinations, or binomial coefcients to understand. But this is easy to count. We have the following combinations oftwo pawns to move one square each (named after their le): abacadaeafagahbcbdbebfbgbhcdcecfcgchdedfdgdhefegehfgfhgh28 possibilities.Note that this is 7+6+5+4+3+2+1. = [...] What is the connection between the number of rows and the> minimum number of dots that must be moved to turn the triangle?> > [...]> > O is dots that has to be moved to turn the triangle.> > O > X X X X > O> > X O X O > X X X X > O X O X O > X X O X X O> X X X X X X > O X X O X X > O> > O > O O > X X X O X X X O> X X X X X X X X > O X X X O X X X > O O> O > Notice how the xed dots are symetrical.> > By observing practical experiments i have created the table below.> B(n) is the number of dots to move.> > n A(n) B(n)> -----------> 1 1 0> 2 3 1> 3 6 2> 4 10 3> 5 15 5> 6 21 7> 7 28 9> 8 36 12> > I get B(6) = 8, No your wrong: O X X X X X X X X X O X X X OO O X X O O> and your pattern implies B(n) = (n-3)(n-2)/2 + 2> for n > 2.hmm > I get B(6) = 8, No your wrong: O> X X> X X X> X X X X> O X X X O> O O X mm-109 Im currently designing a set of interface objects for mac OS X, andone of the possible application would be an interactive spherical trigcourse.The idea is to allow people to mess around with sliders to change thevalues of sides and angles and get immediate feedback, to illustratethat abC always has a solution but abc not, and aAB can have multiplesolutions.Input, especially from those with an interest in teaching sphericaltrig, is appreciated.The OS X InterfaceBuilder palette is available from hort their claims against my argument seemto have a gang that gives them enormous wiggle room.I point out things they cant do, like deliver on coefcients, orevaluate their claims at actual values of x, like x=2, and away theygo as if it doesnt matter in mathematics if you cant actuallyproduce.One person--Rick Decker--at least *tried* to produce on a coefcientquestion, but was foiled by a simple test of his quadratic using x=1,when what happens with another quadratic at x=1 was probably thereason he picked it!!!(Maybe he has another reply to correct his past one by now; Im notseeing it in Google Groups at this time.)So what I see are continual failures to produce by people who despitethat talk a lot.I did a little demonstration where I replied to everyone that repliedto me for a day or so, and you can see the results.The people Im dealing with arent exactly normal, and they cantproduce mathematically.I dont know if others on the newsgroup are cheering them on, not atall interested, or wondering themselves, as they believe mathematicsis more than a social activity, with cliques and groups, where ifyoure out your research is out, and if youre in, hey, you can sayanything! Its like high school in America here!!!Faced with a modern discoverer, not some distant gure in the historybooks, many of you seem to have suddenly decided that math is ademocracy!!!Not saying its related as I cant be sure it is, but as I think itsa telling testimony to modern mathematics and its social reality,heres that quote I like to give:What is a proof? The question has two answers. The right wing(right-or-wrong, rule-of-law) denition is that a proof is alogically correct argument that establishes the truth of a givenstatement. The left wing answer (fuzzy, democratic, and humancentered) is that a proof is an argument that convinces a typicalmathematician of the truth of a given statement.While valid in an idealistic sense, the right wing denition of aproof has the problem that, except for trivial examples, it is notclear that anyone has ever seen such a thing.Sadly, the evidence is in that mathematicians today are not peoplewho care about mathematical truth, but about social truth where itsmostly about what everyone is saying.Yup, mathematics today is, from the evidence Ive seen, a democracy.James Harris Ive noticed that posters who are trapped by being asked to produce> more than vague math to support their claims against my argument seem> to have a gang that gives them enormous wiggle room.> Im sitting in my enormous wiggle room right now. Its quite comfy. Message-id: Ive noticed that posters who are trapped by being asked to produce>> more than vague math to support their claims against my argument seem>> to have a gang that gives them enormous wiggle room.>> Im sitting in my enormous wiggle room right now. Its quite comfy.Are the walls made of rubber?--MensanatorAce of Clubs Ive noticed that posters who are trapped by being asked to produce> more than vague math to support their claims against my argument seem> to have a gang that gives them enormous wiggle room.On the other hand, JSHs arguments are supported by even vaguer claims.And the burden of proof falls entirely on the claimant, not on those who question the claim.Since The claimant, JSH, does not answer the questions, is claim must be rejected, at least until he has answered those claims.For example, Nora has given detailed analyses of where and why JSH is wrong, yet JSHs only responses to them seem to be attempts to psychoanalyse Nora, and ignore the mathematical content of her postings entirely.Either JSHs purposes are psychological, rather than mathematical, or he is not mathematically competent to answer Nora, and others, or both.It is JSH who is making use of wiggle room. Ive noticed that posters who are trapped by being asked to produce> more than vague math to support their claims against my argument seem> to have a gang that gives them enormous wiggle room. On the other hand, JSHs arguments are supported by even vaguer claims. And the burden of proof falls entirely on the claimant, not on those who> question the claim. Since The claimant, JSH, does not answer the questions, is claim must be> rejected, at least until he has answered those claims. For example, Nora has given detailed analyses of where and why JSH is> wrong, yet JSHs only responses to them seem to be attempts to> psychoanalyse Nora, and ignore the mathematical content of her postings> entirely. Either JSHs purposes are psychological, rather than mathematical, or he> is not mathematically competent to answer Nora, and others, or both. It is JSH who is making use of wiggle room.motivations are quite simply to waste your time, and to take some cheapshots at all mathematicians. Ive noticed that posters who are trapped by being asked to produce> more than vague math to support their claims against my argument seem> to have a gang that gives them enormous wiggle room. I point out things they cant do, like deliver on coefcients, or> evaluate their claims at actual values of x, like x=2, and away they> go as if it doesnt matter in mathematics if you cant actually> produce. One person--Rick Decker--at least *tried* to produce on a coefcient> question, but was foiled by a simple test of his quadratic using x=1,> when what happens with another quadratic at x=1 was probably the> reason he picked it!!! (Maybe he has another reply to correct his past one by now; Im not> seeing it in Google Groups at this time.) So what I see are continual failures to produce by people who despite> that talk a lot. I did a little demonstration where I replied to everyone that replied> to me for a day or so, and you can see the results. The people Im dealing with arent exactly normal, and they cant> produce mathematically. I dont know if others on the newsgroup are cheering them on, not at> all interested, or wondering themselves, as they believe mathematics> is more than a social activity, with cliques and groups, where if> youre out your research is out, and if youre in, hey, you can say> anything! Its like high school in America here!!! Faced with a modern discoverer, not some distant gure in the history> books, many of you seem to have suddenly decided that math is a> democracy!!! Not saying its related as I cant be sure it is, but as I think its> a telling testimony to modern mathematics and its social reality,> heres that quote I like to give: (right-or-wrong, rule-of-law) denition is that a proof is a> logically correct argument that establishes the truth of a given> statement. The left wing answer (fuzzy, democratic, and human> centered) is that a proof is an argument that convinces a typical> mathematician of the truth of a given statement. While valid in an idealistic sense, the right wing denition of a> proof has the problem that, except for trivial examples, it is not> clear that anyone has ever seen such a thing.> show that their arguments are correct with mathematics but simply> *convince* other readers are just ne in the math world of today. You see, mathematicians apparently have given up on worrying about> being actually correct, but instead have decided to be like the rest> of the world!!! Maybe next time they give out a Fields Medal they can just have an> election! You can have mathematics political parties, and turn to polls!!! Sadly, the evidence is in that mathematicians today are not people> who care about mathematical truth, but about social truth where its> mostly about what everyone is saying. Yup, mathematics today is, from the evidence Ive seen, a democracy.> James HarrisOk James, If math is a democracy than I propose that we say 2+2=5, whoswith me on this one???Well, Thats not going to get me anywhere because that is obviously wrong,just like your research. You are extremely immature for someone who is anadult. You need to grow up, and while youre at it, learn some math.David Moran Yup, mathematics today is, from the evidence Ive seen, a democracy.> James HarrisYou are an idiot. You want to see science by democracy ?? Look atpsychology.Your math is all awed - even a person such as myself can see that withouteven picking up a pen, and I have never been to skool.If you got your little ass burned on a pre-algebra test then that is YOURproblem. You cannot get grades in math by being a suck-up. Kissing theprofessors ass simply will not work - math is not a humanity.Go learn what you need to learn somewhere, and then they will allow you tograduate, and not before.You cannot take shortcuts in life. There is a sort of isomorphism betweenyour behaviour here and maa-like conduct elsewhere. Grow up, and when youhave learned something, maybe if you beg real hard they will let youretake prealgebra for the Nth time. > >> Littlemanwearingbigboypants misstates yet again:>> >> > Every presidential election year has been a leap year, except for >> http://scienceworld.wolfram.com/astronomy/LeapYear.html>> Gardyloo.When you throw the bucket straight up, move.This site supports Bill Vajk, supposing that he is correct that there>have been presidential elections in 1789, 1800 & 1900, none of which>were leap years.A lot of people who program leap year formulas forget about thecentury exception test. /BAH to remember about our game is that it was designed to keep> our cricketers t in the off season. It is therefore a running and> passing game, no player can keep possession of the ball for more than> a few steps and the ball tends to be in play for a much larger> proportion of the game than Grid Iron. (The most frustrating thing> about watching an American Fottball game is that they will not pass> the ball !, is it actually against the rules ?)No. You may have one forward pass behind the line of scrimage, and youmay perform lateral passes or back pass like in rugby. Not sure if itis allowed ad-innitum... but if only they had more faith in theirplayers, and trained them to handle the ball, surely youd see morepassing in the game. No. You may have one forward pass behind the line of scrimage, and you>may perform lateral passes or back pass like in rugby. Not sure if it>is allowed ad-innitum... Careful, there; youre risking bringing this thread back ontotopic for sci.math.Lee Rudolph > Is it possible to evaluate following integral as a function of k ( 0>Expand the integrand as a power series in k. The coefcient of k^n>>is rational * sin(x)^n; integrate sin(x)^n from 0 to 2*pi (using a>>recursive reduction formula, perhaps). Sum the resulting series.The rational coefcient of k^n sin^n(x), for n >= 2, is n-1> n 2 --- 1 n> (-1) - > - = (-1) H(n-1) [1]> n --- j> j=1Oops, I left out the factor of 2/n in [1], but only there. It should be n-1 n 2 --- 1 n 2 (-1) - > - = (-1) - H(n-1) [1] n --- j n j=1The revised [1] is what is used to get [3] below.>where H(n) is the n^{th} harmonic number.However, the integral from 0 to 2pi of any odd power of sin(x) is 0.>So you only need to consider the even n, and for even n, |2pi n> | sin (x) dx = 2pi C(n,n/2)/2^n [2]> | 0Putting this all together, and substituting n -> 2n, we get that |2pi 2> | ln(1 + k sin(x)) dx> | 0 oo> --- 2n> = 2pi > H(2n-1)/n C(2n,n)/4^n k [3]> ---> n=1The summation in [3] converges absolutely for |k| <= 1.Rob Johnson take out the trash before replying = http://www2.b3ta.com/hawking/ --- Tourettes>> bugger, post some content please, I just disconnected before I>> clicked your post.>> ok, I just got the ash show, not bad, but who was the young cronie besides>> Einstein and hawking?> My guess is Bohr, crossposted to sci.math for the answer.It was Heisenberg. Why sci.math instead of sci.physics?-- Dave SeamanJudge Yohns mistakes revealed in Mumia Abu-Jamal ruling. = http://www2.b3ta.com/hawking/ --- Tourettes>> bugger, post some content please, I just disconnected before I>> clicked your post.>> ok, I just got the ash show, not bad, but who was the young cronie besides>> Einstein and hawking?>> My guess is Bohr, crossposted to sci.math for the answer. It was Heisenberg. Why sci.math instead of sci.physics?>hence : Im not sure.... I dont really know....Heisenberg Uncertainty!Herc = http://www2.b3ta.com/hawking/ ---> Tourettes bugger, post some content please, I just disconnected before I clicked your post. ok, I just got the ash show, not bad, but who was the young cronie>besides Einstein and hawking?>> My guess is Bohr, crossposted to sci.math for the answer.>> It was Heisenberg. Why sci.math instead of sci.physics?>>hence : Im not sure.... I dont really know....>Heisenberg Uncertainty!Worlds Funniest Science Joke:Cop pulls over Heisenbergs car and asksDo you know how fast you were going?To which Heisenberg repliesNo, but I know where I am.>Herc--MensanatorAce of Clubs > see a book tell you that you have learned next to nothing that you should know>> coming into graduate school. Any comments or advice would be appreciated,>> including book suggestions (the author tends to say Ive heard that>> such-and-such book is good though I have not seen it which is pretty odd>> considering the focus of the book).>You may have trouble getting into a top ranked graduate program if>your background is decient. However, whats far more important is>what you do in the graduate school you do get into. Many will allow>you to take a few undergraduate courses to rm up your background. As this problem is rife, that is an understatement. Theyoften also have semi-remedial graduate courses, but thereis too much of a tendency to downplay the weakness of thestudents background.>Another clue to what you will eventually need to know is the book of>problems from UCBerkely qualifying exams published by Springer.However, if one does not know abstract algebra or basicreal analysis, many of the problems will be gibberish.>Dont let snobs tell you that a PhD from a less than top-ranked school>is worthless. It isnt. What is important is to work with an active>and productive researcher with a national (or international)>reputation in his/her eld of research. Such people will make sure>you do a good thesis and will be able to write letters that say what>prospective employers want to hear.This is NOT the case. A long time ago, it was said ofstudents of Loewner that the better the student, theworse the thesis. Another saying is that a thesis is(often) the work of the major professor under adversecircumstances. And I have seen too many candidates witheven good theses and good letters from distinguishedresearchers at rst-class universities who knew far toolittle to consider hiring. Also, the student may havegotten a bad problem, and run into a dead end, or amediocre student may have been lucky. In my many years,I have seen all of these. Predicting what a PhD will doin future research is VERY poor. There are such people even at>lower ranked schools due to the bad job market of recent years. You>may even do better than you might at a top school because as a good>student youll get a lot more attention than you would otherwise.-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University Its just pretty depressing to>> see a book tell you that you have learned next to nothing that you should know>> coming into graduate school. Any comments or advice would be appreciated,>> including book suggestions (the author tends to say Ive heard that>> such-and-such book is good though I have not seen it which is pretty odd>> considering the focus of the book).> >You may have trouble getting into a top ranked graduate program if>your background is decient. However, whats far more important is>what you do in the graduate school you do get into. Many will allow>you to take a few undergraduate courses to rm up your background. > > As this problem is rife, that is an understatement. They> often also have semi-remedial graduate courses, but there> is too much of a tendency to downplay the weakness of the> students background.> >Another clue to what you will eventually need to know is the book of>problems from UCBerkely qualifying exams published by Springer.> > However, if one does not know abstract algebra or basic> real analysis, many of the problems will be gibberish.> >Dont let snobs tell you that a PhD from a less than top-ranked school>is worthless. It isnt. What is important is to work with an active>and productive researcher with a national (or international)>reputation in his/her eld of research. Such people will make sure>you do a good thesis and will be able to write letters that say what>prospective employers want to hear.> > This is NOT the case. A long time ago, it was said of> students of Loewner that the better the student, the> worse the thesis. Another saying is that a thesis is> (often) the work of the major professor under adverse> circumstances. And I have seen too many candidates with> even good theses and good letters from distinguished> researchers at rst-class universities who knew far too> little to consider hiring. Also, the student may have> gotten a bad problem, and run into a dead end, or a> mediocre student may have been lucky. In my many years,> I have seen all of these. Predicting what a PhD will do> in future research is VERY poor.> > There are such people even at>lower ranked schools due to the bad job market of recent years. You>may even do better than you might at a top school because as a good>student youll get a lot more attention than you would otherwise.Of course there are famous professors who cant or wont give theirstudents the right kind of help. Sometimes that help is tellingthem they dont have what it takes to have a career as a researchmathematician. Another point I meant to make is to beware of graduateprograms that exploit graduate students as fodder for teaching lowerlevel courses. Many large university graduate programs do this,loading beginning graduate students with teaching that gets in the wayof proper studying and then, when there are problems completingrequired courses in time or passing qualifying exams before adeadline, the usefulness of the students is over and they are tossedout on the street. Teaching assistantships are a time honored way ofsupporting students through graduate school, but many universitiesbring in marginally qualied students just to use them as cheaplabor. You may have trouble getting into a top ranked graduate program if>your background is decient. However, whats far more important is>what you do in the graduate school you do get into. Many will allow>you to take a few undergraduate courses to rm up your background. > > As this problem is rife, that is an understatement. They> often also have semi-remedial graduate courses, but there> is too much of a tendency to downplay the weakness of the> students background.Have I misunderstood? It sounds like you are saying that when aprogram lets you take a few undergrad courses to rm up, thatsdownplaying the weakness of ones background? Thomas > I need to know how to calculate x^y where y is not an integer. Any>> help in this matter would be appreciated.>ln(x^y) = y*ln(x) ... for x>0>therefore x^y = exp(y*ln(x))First of all, what is x^y, where x > 0? If y = m/n,x^y is the n-th root of x^m, or the m-th power of the n-th root of x. Also, x^y is increasing in y if x > 1, and decreasing in y if x < 1. It is alsocontinuous, and thus one can pass to the limit, andeven obtain bounds. This precedes logarithms.It is also the case, as stated above, that log_b(x^y) = y*log_b(x). BC (before computers),the PRACTICAL calculation was done by using b=10,which made the logarithm tables easier to use,and tted in with scientic notation. Thisis one of the reasons for the use of commonlogarithms, introduced by Briggs. This is how it was done in practice, and this usedto be a standard part of advanced algebra. If onelooks at the texts for these, or for beginners inengineering or scientic computation more than ahalf century ago, this will be found there.-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University = What is known about groups with the property that there are elements > x,y,z in G such that xy=yx, xz=zx, but yz != zy? I admit,> Im asking this question somewhat rhetorically- > because I have found such a group...There are plenty of such groups. The subset of group elements thatcommute with [something] are a topic of interest in Algebra.For example, the set of elements that commute with *every* element ofthe group is called its center. It isnt hard to prove that thecenter of a group is itself an Abelian group.For another example, consider: the set consisting of {1} is itself anabelian subgroup of G. The center is another such. One easily proves(using Kuratowskis ascending chain condition) that G contains amaximal abelian subgroup (which might be the singleton {1}, ofcourse).Centers, maximal abelian subgroups, and commutator subgroups can beused to examine the degree to which a group fails to be abelian.Len. >>Let R be a ring and >>[,]:R*R -> R, [x,y] = xy - yx the commutor function.>>Are those rings for which for all x,y,z in R:>> [x,y] = 0 and [y,z] = 0 -> [x,z] = 0 >>somehow simpler than other rings? If so,>>do any other of any such rings properties follow >>automatically from this?Substituting 1 for y in the above formula, one has [x,z]=0for all x,z in R.Hence, such a ring must be commutative.> The following question did not need the additional complication> of R ring. Let G be a group. What is known about> groups with the property that there are elements > x,y,z in G such that xy=yx, xz=zx, but yz != zy ? I admit,> Im asking this question somewhat rhetorically- > because I have found such a group. Btw., this property > has very little to do with the reasons for me investigating the> group found as of yet.Every noncommutative group satises the above with x=1.Marc =What is the vector space structureof xed rank (k), (n x n) matrices ?What are the canonical bases for each k ? space structure> of xed rank (k), (n x n) matrices ?The set of all nxn matrices of rank k with sum and multiplication by a scalaris not a vector space. Indeed, the sum of 2 matrices of rank k is not, as ageneral rule, a rank k matrix. (take a matrix A that has rank k. -A has rankk too, and A + (-A) = 0, so it has rank 0).Sam-- So if you meet me, have some courtesy, have some sympathy, and some taste Use all your well-learned politesse, or Ill lay your soul to waste - The Rolling Stones, Sympathy for the Devil = .....................>> I hope the quote alludes to the fact that naming systems arent only a>> problem in mathematics, but perhaps it would be productive to restrict>> the discussion to math despite this obvious fact.>Naming is a matter of historical accident, historical inaccuracy, and >human whim. Most theorems (can I say most? at least some.) were rst >proved by someone other than their associated name. Fermats Last >Theorem being the classic case.Stigler claims that this is always the case. Theclassical ones in statistics are Bayes Theorem (althoughthe earlier source can only be conjectured) and theGaussian distribution, discovered by de Moivre 47 yearsbefore Gauss was born.>Then of course why is it Zorns Lemma, the Axiom of Choice, and the >Well-Ordering Principle?BTW, Zorn did not explicitly credit it, but he did givea reference to the book by R. L. Moore, who refers tothe paper of Kuratowski. What is the difference among lemma, axiom, and >principle, if in this case they are used to label logical propositions >known to be equivalent to one another?Zorn used it to assist in algebraic proofs, and he wasusing it as a substitute for the Axiom of Choice orthe Well-Ordering Principle. This is the purpose ofa lemma. BTW, Zorn was the rst to state that itimplied AC, although he never published the proof; Iknow this from personal conversation. An axiom isexplicitly assumed, and generally not believed to follow from the other assumptions. A principle isa property which is directly used. When they wereintroduced, AC and WO were not known to be equivalent;Zermelo proved that AC implied WO, the converse beingtrivial. That WO implies ZL is trivial, although Kuratowski proved it directly from AC.>You might as well campaign for geographical names to make logical sense.-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University =Suppose you wish to study a given population using statistics, but there isno way to determine with certainty that your population actually satisesthe criteria which dene that population. Example - we would like to know the approximate dimensions ofapparitions or poltergeists. We would like to know how large the averagepoltergeist is. Unfortunately, there is no way to determine with certainty that we haveamassed a sample or even a population of poltergeists, nor can we reallymeasure their dimensions. Yet, we would like to know the average size of aghost.Is statistics possible in this case ?? Can one make determnations regardingsuch a population of ghosts ?Can statistics be deployed correctly in such a case as this ??This may sound like a completely stupid question - but I am %100 serious.This is NOT a troll. This question needs to be asked. =of the solutions came across this little equation:x^2 + x + 1 = 0 (i)For fun, I started to push things around a bit, instead of just goingwith x = (-b +- sqrt(b^2 - 4ac))/(2a):x(x + 1) = -1(x + 1) = -1/x (ii) <-- I though it would be OK to divide by x,since x<>0Substituting (ii) back into (i):x^2 + (x + 1) = 0x^2 - 1/x = 0x^3 - 1 = 0 <-- again, multiplying by x, since x<>0(x - 1)(x^2 + x + 1) = 0 (iii)Somehow in my little manipulations I introduced a new factor onto theoriginal equation, but I cant gure out how. This seems prettyridiculous, but Id appreciate another pair of eyes looking at it andletting me know where the (x - 1) factor popped in.Jeff of the solutions came across this little equation:> > x^2 + x + 1 = 0 (i)> > For fun, I started to push things around a bit, instead of just going> with x = (-b +- sqrt(b^2 - 4ac))/(2a):> > x(x + 1) = -1> > (x + 1) = -1/x (ii) <-- I though it would be OK to divide by x,> since x<>0> > Substituting (ii) back into (i):> > x^2 + (x + 1) = 0> > x^2 - 1/x = 0> > x^3 - 1 = 0 <-- again, multiplying by x, since x<>0> > (x - 1)(x^2 + x + 1) = 0 (iii)> > > Somehow in my little manipulations I introduced a new factor onto the> original equation, but I cant gure out how. This seems pretty> ridiculous, but Id appreciate another pair of eyes looking at it and> letting me know where the (x - 1) factor popped in.> > JeffReplacing (x + 1) with -1/x changed an equation which is false for x=1into an equation which is true for x=1.Your (i) is equivalent to your (ii), and that statement implies (iii),but (iii) does not imply (i). When solving equations, it is generally agood idea to watch your steps so that you dont end up with statementsthat are more generally true.Or to put it another way, whenever x-2=0, you can safely conclude that xis in the set {1, 2}. However, that conclusion is not minimal; the set{2} would work as well.If you want a specic answer for this case, note that if the originalequation is written as p(x) = 0, the substitution ended up beingequivalent to subtracting p(x)/x from the left side of the equation(using the fact that p(x) = 0 implies p(x)/x = 0). This subtraction wasequivalent to multiplying both sides by (1 - 1/x). The connection to (x- 1) should be obvious. -- Daniel W. Johnsonpanoptes@iquest.nethttp://members.iquest.net/~panoptes /039 53 36 N / 086 11 55 W of the solutions came across this little equation:> > x^2 + x + 1 = 0 (i)> > For fun, I started to push things around a bit, instead of just going> with x = (-b +- sqrt(b^2 - 4ac))/(2a):> > x(x + 1) = -1> > (x + 1) = -1/x (ii) <-- I though it would be OK to divide by x,> since x<>0> > Substituting (ii) back into (i):> > x^2 + (x + 1) = 0> > x^2 - 1/x = 0> > x^3 - 1 = 0 <-- again, multiplying by x, since x<>0> > (x - 1)(x^2 + x + 1) = 0 (iii)> > > Somehow in my little manipulations I introduced a new factor onto the> original equation, but I cant gure out how. This seems pretty> ridiculous, but Id appreciate another pair of eyes looking at it and> letting me know where the (x - 1) factor popped in.> > JeffYou have introduced an extraneous root to your equation.The roots of x^3 - 1 = 0 are the 3 cube roots of 1.The roots of x^2 + x + 1 - 0 are the 2 primitive cube roots of 1.The extraneous root creeps in as a result of your substituting -1/x for x + 1, since that effectively changes the degree of the equation. of the solutions came across this little equation: x^2 + x + 1 = 0 (i) For fun, I started to push things around a bit, instead of just going> with x = (-b +- sqrt(b^2 - 4ac))/(2a): x(x + 1) = -1 (x + 1) = -1/x (ii) <-- I though it would be OK to divide by x,> since x<>0 Substituting (ii) back into (i): x^2 + (x + 1) = 0Another poster has already given the gist of the matter, butjust to make things completely explicity, at this point youare going to use the fact If x^2 + (x+1)=0 and (x+1)=-1/x, then x^2 -1/x = 0.The reverse, of course, does not hold. That is, x^2-1/x=0 does not imply that (x+1)=-1/x and x^2+x+1=0.(Obviously, it implies neither, as you have observed thatx=1 is a solution to x^2-1/x=0 but not a solution to eitherx^2+x+1=0 or (actually, equivalently) x+1=-1/x. ) x^2 - 1/x = 0 x^3 - 1 = 0 <-- again, multiplying by x, since x<>0 (x - 1)(x^2 + x + 1) = 0 (iii)> Somehow in my little manipulations I introduced a new factor onto the> original equation, but I cant gure out how. This seems pretty> ridiculous, but Id appreciate another pair of eyes looking at it and> letting me know where the (x - 1) factor popped in.Have fun! Keep thinking!Best wishes, Mike of the solutions came across this little equation:> > x^2 + x + 1 = 0 (i)> > For fun, I started to push things around a bit, instead of just going> with x = (-b +- sqrt(b^2 - 4ac))/(2a):> > x(x + 1) = -1> > (x + 1) = -1/x (ii) <-- I though it would be OK to divide by x,> since x<>0> > Substituting (ii) back into (i):> > x^2 + (x + 1) = 0> > x^2 - 1/x = 0> > x^3 - 1 = 0 <-- again, multiplying by x, since x<>0> > (x - 1)(x^2 + x + 1) = 0 (iii)> > > Somehow in my little manipulations I introduced a new factor onto the> original equation, but I cant gure out how. This seems pretty> ridiculous, but Id appreciate another pair of eyes looking at it and> letting me know where the (x - 1) factor popped in.What you have proved was that x^2 + x + 1 = 0 (x - 1)(x^2 + x + 1)and this is obviously correct. It would still be correct if x - 1 wasreplaced by anything else. But note that your computations do not provethe reverse implication: you cannot devide by x - 1 since you are notassuming that x <> 1.Jose Carlos Santos > The problem here is so simple. You assume a factorization > > of your polynomial P(x) of the form> >> > > >> > (*) (5*a1(x) + 7)*(5*a2(x) + 7)*(5*b3(x) + 22).> >> > >> Thats like saying that someone assumes that sqrt(2) is a factor of 2.> >> > >> Factorizations just exist.> >> > >> > >> I am just summarizing what you have said. I am not> >> disagreeing with it, at least not at this point.> >Yeah, like what if someone says, lets assume that 6 has 3 as a> >factor.Technically its correct.> >But the use of the word assume looks strange there, as 3 IS a factor> >of 6.> > Typically an expression can be factored lots of ways. You assumed a> factorization of the specied form. I see absolutely nothing> wrong with my wording and I dont agree that it looks strange.> In any case this is an utterly minor issue. > > > A person might assume that theyre sounding rational, and cogent, when> in fact theyre sounding defensive and recalcitrant.> > You dont just assume a truth. > > Ill give you another example as Im somewhat curious about your state> of mind.> > Lets say that I make it a point to say I assume that the sun will> rise tomorrow.> > Isnt there some implication in that statement to you?> The analogy doesnt work. There are lots of ways to factoran expression. If I said, What is the form of thefactorization of (125*x^3 + 75*x^2 + 45*x + 7)?, most peoplemight think I wanted a factorization as a polynomial in x. That, however, is not what you have done with your expression.You have factored it as a polynomial in 5. That is why itis important to say that you *assumed* a factorization ofthe specied form. It is a natural and even necessary part of the discussion. And here, its a distraction. You are trying desperately to focuson a minor wording issue to take attention away from the factthat you have not dealt with the mathematics.> > >Theres no need to assume anything.> >Now it seems to me that youre playing stupid when the obvious is> >pointed out to you.> > Youre quibbling over a minor wording issue. Meanwhile you> delete and evade the underlying math below.> > > Is that an assumption on your part?> No. Its like saying the sun will rise tomorrow.> >> > >> > > >> > You note that since P(x) is divisible by 49, there must be> >> > some way to factor 49 out of the terms in (*). You think> >> > that the only possible way such a factorization can occur> >> > is of the form 7, 7, 1. But you know that assuming a factorization > > >> And now you claim to know what I *think*?> >> > >> > >> > You have said it many times.> >Then give a single quote.> > OK, how about one that you posted YESTERDAY in the thread> Mathematical consistency, courage ?> > The constant terms are 7, 7, and 22, but when 49 is divided> off the resulting constant terms are 1, 1, and 22, which means> from BASIC arithmetic, theres only one way to go.> > There is, in fact, only one way that can happen.> > > Yup, now then, look back at your claim about what I thought.> OK. (Looks back). Yes, by Jove, they are identicalin meaning.> >Here youre caught, yet again, but rather than acknowledging the> >obvious--you cant read minds--you instead toss out yet another> >statement.> > See above. That was a direct, unedited quote. I cant read > minds but I can read what you post. So can everyone else who> sees this. > > > Yup. Now then, look carefully back at what *you* said I thought, and> Im curious to hear how you feel that the quote you gave is saying the> same thing.> > Be quite detailed please.> I said you thought that the only way to split 49 into three factors that would divide the three terms of (5 a_1(x) + 7)*(5 a_2(x) + 7)*(5 b_3(x) + 22)was as 49 = 7 * 7 * 1, where the rst 7 divides (5 a_1(x) + 7),the second 7 divides (5 a_2(x) + 7), and 1 divides (5 b_3(x) + 22).And indeed, that is precisely, exactly what you claimed. If you now want to retract that, ne with me. That wouldopen the door to other factorizations of 49 - for example49 = w1(x)*w2(x)*w3(x), where w1(x), w2(x), and w3(x) arenon-unit algebraic integers, and for x <> 0, none of themare equal to 7. If you are now willing to contemplate factorizations like that, rather than your inspection-basedfactorization 7, 7, 1, then your whole edice collapses.So, retract away!> > >So I challenge you to give a single quote.> > > > Done. See above. I await your explanation.> > > Its very simple. In fact, Ive been rather detailed about my> factorization, and how it works.> > But you make statements that are attempts at trying to change the> facts.> Such as???> Like even though you gave that quote, you then didnt even bother to> reconcile obvious differences!> > Like you have 7, 7, 1, while I talk of 7, 7 and 22.> Oh, PLEASE!!! One of these is your proposed factorizationof 49. The other is the constant terms of your factorizationof P(x). If you think I have claimed they are the same, youare simply delusional. You clearly, unambiguously think, as you said in the quote, that the only way to factor 49 through the threelinear factors of P(x) was as 7, 7, and 1. There is no doubt> Its something Ive watched before in your postings where you make> little mistakes, big mistakes, and strange mistakes, but when its> pointed out, you always deny!!!> I ask of you what you asked of me: provide one example.> Later, I catch you making the *same* mistakes, and with VERY long> posts, as if part of your strategy is burying your behavior with a lot> of verbiage.> This whole exchange is simply surreal. I make a statement aboutwhat you thought. You say I am falsely reading your mind. I provide a direct quote from 1 day before which proves 100% ofwhat I said about your thinking. You squirm and turn and tryto weasel out of it. You try to deny the meaning of your own quotation. WHO THE HELL ARE YOU TRYING TO FOOL, ANYWAY ?> Its kind of interesting behavior, though bizarre. >> > >> > >> Who cares what I think, > >> > >> > >> You have made a huge error. My interest is in trying to> >> get you to realize it.> >> > >I dont think so. For instance, a while back in response to your> > I will never, never engage in any nonpublic conversations with> you on any topic.> > So now you *nally* admit that you need an audience. Why do I have> to drag the truth out of you?> I dont want an audience. I want witnesses. I would never trustyou to quote anything I said o'ne. > You make claims that dont t with your behavior. > >Now then, why dont you try again and explain what you *really* are> >trying to do?> > Its simple. I am trying to show you that your factorization of 49 > in the 7, 7, 1 pattern is the WRONG FACTORIZATION when x <> 0. Needless > to say you are not getting it. > > Now theres one of the errors YET AGAIN, and I have to admit that its> a puzzle to me. OK, I will say it as succinctly and clearly as I possibly can. You divide (5 a_1(x) + 7)*(5 a_2(x) + 7)*(5 b_3(x) + 22)by 49. You split 49 into 3 pieces: say, 49 = A*B*C.Your goal is for each of (5 a_1(x) + 7) / A, (5 a_2(x) + 7) / B, and (5 b_3(x) + 22) / Ceach to be algebraic integers.You say the ONLY POSSIBLE hope of achieving this is tospecify: A = 7, B = 7, C = 1,because that is the only conguration that dividesthe constant terms as you want. We say NO. For one thing, as you now acknowledge, A = 7, B = 7, and C = 1 does NOT WORK in general: in particular, (5 a_1(x) + 7) / 7 is NOT an algebraic integer for most x <> 0. You know this. But there is ANOTHER CHOICE for A, B, and C whichDOES work, to make all of the three quotients abovealgebraic integers. For that choice, each of A, B,and C are dependent on x. Yes, when x = 0, A = 7, B = 7, and C = 1. But when x <> 0, this is no good,and other numbers must be chosen. Now: your objection to this amounts to sayingthat if C is a factor of 49 which is not a unit,then 22/C cannot be an algebraic integer. If that is what you think, YOUR ARE ABSOLUTELY, TOTALLY RIGHT! And that conclusion is ABSOLUTELY, TOTALLY IRRELEVANT!There is not the slightest reason to want 22/C tobe an algebraic integer. What you MUST have is that (5 b_3(x) + 22) / Cis an algebraic integer. Do you see the difference? Is there any hope atall that this key concept can penetrate to your tinylittle brain ? Or are you too far gone in delusion-land ? > Do you do that consciously? Or is there something> deeper and even more odd going on here?> You can easily gure that out by responding in detail to themath in my original post. Enough with the distractions and the smoke-screen about wording, your ridiculous attempt to deny the meaning of your own quotations, and your obsession with social interaction. > Appended again is my post which you keep deleting -> clearly you dont want people to read it - and to which you> have not yet given any substantive mathematical response:> > No, thats not it. Ive seen your posting pattern before, and found> that after spending time and effort to correct your mistakes and> explain to you, you simply deny the truth, or just come back before below, giving you againyour *rst* chance to actually deal with the math. > Its rather bizarre, but now kind of interesting.> Whats bizarre is that you keep deleting the appended toavoid dealing with the math and to keep your imaginary fans from reading it!> > James Harris problem here is so simple. You assume a factorization > of your polynomial P(x) of the form> > (*) (5*a1(x) + 7)*(5*a2(x) + 7)*(5*b3(x) + 22).> > You note that since P(x) is divisible by 49, there must be> some way to factor 49 out of the terms in (*). You think> that the only possible way such a factorization can occur> is of the form 7, 7, 1. But you know that assuming a factorization > of the form 7, 7, 1 leads to a contradiction. The contradiction> can be proved in two totally different ways: by using Galois> theory, and by using a basic theorem in algebraic number> theory.> > You conclude from this contradiction that there is a > problem with the algebraic integers.> > What you *should* conclude is that your claim that the only> way the factorization can occur is 7, 7, 1 is wrong. > > Look hard. You do not really have a proof of that claim.> You have a handwaving argument based on your concept of> constant terms of functions.> > You think your argument that such a factorization would> have to be 7, 7, 1 is ironclad. It is based on the idea> that the constant terms in (*) are 7, 7, and 22, and in particular> 22 is coprime to 7. Therefore you conclude that the third> factor must be 1.> > You overlook the fact that when x <> 0, 5*b3(x) + 22 can be > non-coprime to 7 even though 22 and 7 have no nonunit factors > in common.> > We say you are wrong about 7, 7, 1. There is another way > to factor 49 through the terms in (*). Dik Winter and others have> described it explicitly. It is not 7, 7, 1. It is> w1(x), w2(x), w3(x), where each of these is a non-unit> algebraic integer factor of 49. None of w1, w2, or w3 are> equal to 7. In particular, for example, 5*b3(x) + 22 is > divisible by w3(x). No contradiction arises. The arithmetic > works out. The constant terms multiple as they should > to 49*22.> > The real root of the problem is that you are doing > factorization by inspection, as in high school. You see those> constant terms 7, 7, and 22. The temptation to conclude > that the factorization of 49 must be as 7, 7, 1 is > overwhelming. You cannot imagine it could be any other> way. Your many simplistic examples involving reducible> polynomials work out as you expect. How could it be> otherwise in this case?> > It is! The key thing here is that for x <> 0 in general,> the polynomials involved are irreducible. They simply do> not act like the ones in the high-school textbooks. They> factor in ways that you do not expect. In some ways their> properties can defy intuition. A key fact is that 7> is not a prime in the algebraic integers. It can be > factored in innitely many different ways. One such> factor is w1(x) which Dik has specied exactly as:> > w1(x) = gcd(a1(x), 49),> > where a1(x) is a root of > > (**) a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x).> > This is an explicit specication in the sense that > (1) the roots of the cubic (**) can be computed explicitly, and > (2) there is a specic algorithm for computing the gcd> function in the algebraic integers (due to Dedekind).> > Your factorization leads you to a contradiction. What> that should tell you is that you have made a mistake. Nevertheless> you perversely cling to it and refuse to see that another> factorization is possible. Our factorization has no > such problem. It makes sense and is consistent with > existing theory. The factorization itself is dependent on> the value of x. This should not be surprising, since> the values of a1(x), a2(x) and b3(x) are dependent on x.> In no way is this weird or bizarre. > > math can take you only so far. In this case, not quite far> enough. > > > Nora B. The problem here is so simple. You assume a factorization > > of your polynomial P(x) of the form> >> > > >> > (*) (5*a1(x) + 7)*(5*a2(x) + 7)*(5*b3(x) + 22).> >> > >> Thats like saying that someone assumes that sqrt(2) is a factor of 2.> >> > >> Factorizations just exist.> >> > >> > >> I am just summarizing what you have said. I am not> >> disagreeing with it, at least not at this point.> >Yeah, like what if someone says, lets assume that 6 has 3 as a> >factor.Technically its correct.> >But the use of the word assume looks strange there, as 3 IS a factor> >of 6.> > > > Typically an expression can be factored lots of ways. You assumed a> > factorization of the specied form. I see absolutely nothing> > wrong with my wording and I dont agree that it looks strange.> > In any case this is an utterly minor issue. > > > > A person might assume that theyre sounding rational, and cogent, when> in fact theyre sounding defensive and recalcitrant.> > You dont just assume a truth. > > Ill give you another example as Im somewhat curious about your state> of mind.> > Lets say that I make it a point to say I assume that the sun will> rise tomorrow.> > Isnt there some implication in that statement to you?> > > The analogy doesnt work. There are lots of ways to factor> an expression. If I said, What is the form of the> factorization of (125*x^3 + 75*x^2 + 45*x + 7)?, most people> might think I wanted a factorization as a polynomial in x. > That, however, is not what you have done with your expression.> You have factored it as a polynomial in 5. That is why it> is important to say that you *assumed* a factorization of> the specied form. It is a natural and even necessary > part of the discussion.Lets say you assume that irrationals are not integers.Yet someone else tells you, hey, why assume that, as theyre just not?Dont you think a *rational* response might be to go, oh, yeah, youreright?Now then, what if instead, you acted defensive and argued endlesslyabout your use of words where there was an implication that somethingmight not be true by use of the word assume, which *reasonable*people could see.Is there any possibility that you might concede that saying assumefor a truth might be loaded or could look like youre trying to implythat something might not be true? > And here, its a distraction. You are trying desperately to focus> on a minor wording issue to take attention away from the fact> that you have not dealt with the mathematics.> Im curious about how you manage to spend so much time ratherobviously ignoring the truth, twisting things a certain way, yetacting as if youre aboveboard no matter how often youre caught.Your defensive reaction here with the word assume is a case inpoint.You basically refuse to be rational, and refuse to concede even minorpoints, arguing endlessly as if youre always right, no matter what,or how much evidence is produced to challenge your world view.> > > > >Theres no need to assume anything.Now it seems to me that youre playing stupid when the obvious is> >pointed out to you.> > > > Youre quibbling over a minor wording issue. Meanwhile you> > delete and evade the underlying math below.> > > > Is that an assumption on your part?> > > > No. Its like saying the sun will rise tomorrow.> So then, is my use of the word assumption appropriate in context toyou?Can you see it as communicating something by its use?> > >> > >> > > >> > You note that since P(x) is divisible by 49, there must be> >> > some way to factor 49 out of the terms in (*). You think> >> > that the only possible way such a factorization can occur> >> > is of the form 7, 7, 1. But you know that assuming a factorization > >> > >> And now you claim to know what I *think*?> >> > > >> > >> You have said it many times.> >Then give a single quote.> > > > OK, how about one that you posted YESTERDAY in the thread> > Mathematical consistency, courage ?> > > > The constant terms are 7, 7, and 22, but when 49 is divided> > off the resulting constant terms are 1, 1, and 22, which means> > from BASIC arithmetic, theres only one way to go. > > There is, in fact, only one way that can happen.> > > > Yup, now then, look back at your claim about what I thought. > OK. (Looks back). Yes, by Jove, they are identical> in meaning.No they are not. Im noting that constants, like 7, or 22, cant turninto some other number out of thin air. There has to be an operationthat takes place. In this case you get a transformation from constantterms 7, 7 and 22 to a result with constant terms 1, 1, and 22.That requires that 7 becomes 1 after that operation.In this case the operation is division, and 7 *has* to have beendivided by 7, to give the result 1.Now then, look *again* at what you said, and see if you can begin tosee differences in your claims about what I *thought* and myexplanation of what Ive said. > > >Here youre caught, yet again, but rather than acknowledging theobvious--you cant read minds--you instead toss out yet another> >statement.> > > > See above. That was a direct, unedited quote. I cant read > > minds but I can read what you post. So can everyone else who> > sees this. > > > > Yup. Now then, look carefully back at what *you* said I thought, and> Im curious to hear how you feel that the quote you gave is saying the> same thing.> > Be quite detailed please.> > > I said you thought that the only way to split 49 into three > factors that would divide the three terms of> > (5 a_1(x) + 7)*(5 a_2(x) + 7)*(5 b_3(x) + 22)> > was as 49 = 7 * 7 * 1, where the rst 7 divides (5 a_1(x) + 7),> the second 7 divides (5 a_2(x) + 7), and 1 divides (5 b_3(x) + 22).> And indeed, that is precisely, exactly what you claimed.Nope. I talked about the *constant* terms in those factors, and notedthat those constant terms changed, and that there was only one way forthem to change.Even now you STILL dodge and twist to try and challenge the facts.Im being very specic here for a reason, but if you havemathematical expertise then you should appreciate being VERY specic.Can you begin to see differences between what youre saying and whatIm saying?> > If you now want to retract that, ne with me. That would> open the door to other factorizations of 49 - for example> 49 = w1(x)*w2(x)*w3(x), where w1(x), w2(x), and w3(x) are> non-unit algebraic integers, and for x <> 0, none of them> are equal to 7. If you are now willing to contemplate > factorizations like that, rather than your inspection-based> factorization 7, 7, 1, then your whole edice collapses.> So, retract away!> My position still remains that if you have *constants* 7, 7 and 22,and then have 1, 1, and 22, after dividing by 49, its a matter ofsimple arithmetic to determine what happened.Now theres a difference between that and what youre claiming.> > > > >So I challenge you to give a single quote.> > > > > > Done. See above. I await your explanation.> > > > Its very simple. In fact, Ive been rather detailed about my> factorization, and how it works.> > But you make statements that are attempts at trying to change the> facts.> > > Such as???Now you play dumb. > Like even though you gave that quote, you then didnt even bother to> reconcile obvious differences!> > Like you have 7, 7, 1, while I talk of 7, 7 and 22.> > > Oh, PLEASE!!! One of these is your proposed factorization> of 49. The other is the constant terms of your factorization> of P(x). If you think I have claimed they are the same, you> are simply delusional. You clearly, unambiguously think, as you > said in the quote, that the only way to factor 49 through the three> linear factors of P(x) was as 7, 7, and 1. There is no doubtAnd now youre STILL trying to mindread. Now I didnt understand whatyou meant by 7, 7 and 1 before, but now I do, and it makes sense thatI didnt as I keep saying 7, 7 and 22 talking about the constantterms.As for your claim about ways to factor 49, thats just somethingyoure making up.What I *say* is that the constant terms go from being 7, 7 and 22 tobeing 1, 1, and 22, when 49 is divided off, which is an easilyveriable fact. > Its something Ive watched before in your postings where you make> little mistakes, big mistakes, and strange mistakes, but when its> pointed out, you always deny!!!> > > I ask of you what you asked of me: provide one example.> My replies to your posts here are examining your behavior, so you needonly consult them.> > Later, I catch you making the *same* mistakes, and with VERY long> posts, as if part of your strategy is burying your behavior with a lot> of verbiage.> > > This whole exchange is simply surreal. I make a statement about> what you thought. You say I am falsely reading your mind. I > provide a direct quote from 1 day before which proves 100% of> what I said about your thinking. You squirm and turn and try> to weasel out of it. You try to deny the meaning of your own > quotation. WHO THE HELL ARE YOU TRYING TO FOOL, ANYWAY ?Im curious about how you go about what youre doing, to see if itsconscious, or unconscious as Im curious. > > Its kind of interesting behavior, though bizarre.> > >> > >> > >> Who cares what I think, > >> > >> > >> You have made a huge error. My interest is in trying to> >> get you to realize it.> >> > >I dont think so. For instance, a while back in response to your> > I will never, never engage in any nonpublic conversations with> > you on any topic.> > So now you *nally* admit that you need an audience. Why do I have> to drag the truth out of you?> > > I dont want an audience. I want witnesses. I would never trust> you to quote anything I said o'ne. How is that relevant to your claims about your purpose?Why dont you say what your purpose really is?> > You make claims that dont t with your behavior.> > > > >Now then, why dont you try again and explain what you *really* are> >trying to do?> > > > Its simple. I am trying to show you that your factorization of 49 > > in the 7, 7, 1 pattern is the WRONG FACTORIZATION when x <> 0. Needless > > to say you are not getting it. > > Now theres one of the errors YET AGAIN, and I have to admit that its> a puzzle to me. > > > OK, I will say it as succinctly and clearly as I possibly can.> > You divide > > (5 a_1(x) + 7)*(5 a_2(x) + 7)*(5 b_3(x) + 22)> > by 49. You split 49 into 3 pieces: say, 49 = A*B*C.> Your goal is for each of > > (5 a_1(x) + 7) / A,> > (5 a_2(x) + 7) / B, and> > (5 b_3(x) + 22) / C> > each to be algebraic integers.No. Thats not true. My point is that in generaly they are NOTalgebraic integers.Surely that should be something that you can now accept so that you nolonger say what you just did, right?That is, are you no longer going to claim that I say that after 49 isdivided off from both sides that you still have algebraic integers,since Ive just told you explicitly thats not what Im saying? > > You say the ONLY POSSIBLE hope of achieving this is to> specify:> > A = 7, B = 7, C = 1,> > because that is the only conguration that divides> the constant terms as you want.> > We say NO. For one thing, as you now acknowledge, > A = 7, B = 7, and C = 1 does NOT WORK in general: > in particular,> > (5 a_1(x) + 7) / 7 > > is NOT an algebraic integer for most x <> 0.> > You know this.Then why did you claim above that I make an opposite claim?Can you see what Im seeing here? Is there any part of you thatacknowledges that, hey, other people reading might wonder whats goingon with you? James Harris analogy doesnt work. There are lots of ways to factor>> an expression. If I said, What is the form of the>> factorization of (125*x^3 + 75*x^2 + 45*x + 7)?, most people>> might think I wanted a factorization as a polynomial in x.>> That, however, is not what you have done with your expression.>> You have factored it as a polynomial in 5. That is why it>> is important to say that you *assumed* a factorization of>> the specied form. It is a natural and even necessary>> part of the discussion.Lets say you assume that irrationals are not integers.Yet someone else tells you, hey, why assume that, as theyre just not?Dont you think a *rational* response might be to go, oh, yeah, youre>right?> Again not a valid parallel. This argument is so goddamned sillyand petty. I have little patience with arguments about semantic trivia. If you dont like my saying that you assumed a factorization of the form given, you can replace assumed by specied. That conveys the same meaning: that there were lots of other ways it could have been specied (or assumed for that matter).>Now then, what if instead, you acted defensive and argued endlessly>about your use of words where there was an implication that something>might not be true by use of the word assume, which *reasonable*>people could see.Is there any possibility that you might concede that saying assume>for a truth might be loaded or could look like youre trying to imply>that something might not be true?> And here, its a distraction. You are trying desperately to focus>> on a minor wording issue to take attention away from the fact>> that you have not dealt with the mathematics.>>Im curious about how you manage to spend so much time rather>obviously ignoring the truth, twisting things a certain way, yet>acting as if youre aboveboard no matter how often youre caught.Your defensive reaction here with the word assume is a case in>point.You basically refuse to be rational, and refuse to concede even minor>points, arguing endlessly as if youre always right, no matter what,>or how much evidence is produced to challenge your world view.> No, youre simply wrong. You assumed a factorization of acertain form. You could have assumed many other forms. Itis appropriate to note what you did and to convey the impressionthat the choice involved a decision on your part. By no meanswas I implying that your assumption was wrong. Its not.There IS a factorization of that form. I was just describing thatthat was the form you were specifying..>> > >Theres no need to assume anything.>> > >Now it seems to me that youre playing stupid when the obvious is>> >pointed out to you.>> > > > Youre quibbling over a minor wording issue. Meanwhile you> delete and evade the underlying math below.>> > Is that an assumption on your part?>> No. Its like saying the sun will rise tomorrow.>>So then, is my use of the word assumption appropriate in context to>you?> You are not describing an analogous usage. It makes no senseto describe it as an assumption; no other alternativesneed be contemplated or excluded. That is not the case, however,with your factorization. Many other equally plausible, validchoices were available.>Can you see it as communicating something by how about one that you posted YESTERDAY in the thread>> > Mathematical consistency, courage ?>> > > The constant terms are 7, 7, and 22, but when 49 is divided>> > off the resulting constant terms are 1, 1, and 22, which means>> > from BASIC arithmetic, theres only one way to go.>> > > There is, in fact, only one way that can happen.>> > Yup, now then, look back at your claim about what I thought.>> OK. (Looks back). Yes, by Jove, they are identical>> in meaning.No they are not. Im noting that constants, like 7, or 22, cant turn>into some other number out of thin air. There has to be an operation>that takes place. In this case you get a transformation from constant>terms 7, 7 and 22 to a result with constant terms 1, 1, and 22.> By the slowest possible steps, we approach the truth: againstyour kicking and screaming every millimeter of the way. Yes, *you* want to end up with 1, 1, 22 in place of the constantterms after the factorization. That is the problem. To youthat is the only conceivable result of what can happen afterthe division has occurred. You cannot conceive that afterthe division of the constant terms, you might have 7/A 7/Band 22/C,where A*B*C = 49 and (most importantly) where 22/C is NOTan algebraic integer. This is the central problem. You think it is absolutelynecessary, after division of both sides by 49, that22/C be an algebraic integer. That causes you to conclude, since 7 and 22 are coprime, that C = 1. Anything else is just plain beyond your imagining. But anything else is precisely what happens. For x <> 0in general, 49 can be factored into three factors, A, B, and C, allof them algebraic integers, none of them a unit, none ofthem equal to 7, such that (5 a_1(x) + 7) / A, (5 a_2(x) + 7) / B,and (5 b_3(x) + 22) / Care ALL algebraic integers. What you dont seem to understandis that, ***even if 22/C is not an algebraic integer***, it isperfectly possible that (5 b_3(x) + 22) / CIS one. And that is sufcient. Why ? Because on one sideof the equation you have P(x)/49, which is clearly and unambiguouslyan algebraic integer. And on the other side of the equation youhave [(5 a_1(x) + 7)/A]*[(5 a_2(x) + 7)/B]*[5 b_3(x) + 22)/C]which is nothing more than the product of three algebraicintegers. AND THAT IS WHAT YOU NEED. YOU DONT NEED THAT22/C IS AN ALGEBRAIC INTEGER. I should note also, however, that if you go back andre-write (5 b_3(x) + 22) as, instead, (5 a_3(x) + 7), anddivide *that* by C, you get (5 a_3(x) + 7)/C = 5 a_3(x)/C + 7/C,and it WILL be the case that 5 a_3(x)/C and 7/C areboth algebraic integers. The same is true for a_1(x)/A,a_2(x)/B, 7/A, and 7/B. Putting it all together, youget a complete factorization of P(x)/49 of the form (5 c_1(x) + d1(x))*(5 c_2(x) + d2(x))*(5 c_3(x) + d3(x))where EVERY COEFFICIENT is an algebraic integer. This is exactlythe sort of thing that you get from the Magidin-Mckinnonresult. It is a factorization of the form you were aimingfor. Remember? And you CANNOT GET THERE by the 7, 7, 1 pattern.You CAN, and you MUST factor 49 so that all three factors A,B, and C, are not co-prime to 7 !>That requires that 7 becomes 1 after that operation.> Yes. Your assumption that the factorization has to be 7, 7, 1comes as a result of your assumption that the constantterms after the division must be 1, 1, and 22. AND THATASSUMPTION IS FALSE. THAT is where you are making your mistake. There is *another* factorization which gives algebraicintegers on both sides of the equation. 49 divides out of the right side of the equation to yield a product of factors with algebraic integer coefcients, just as it should. You should go back and look at the Rick Decker thread.Compute the analog of 22/C for *his* factorization: youwillfind that when x = 1, it is 2/sqrt(7), which is notan algebraic integer. Yet as I note also in that thread, Q(1)/7 = (5*sqrt(-2) + sqrt(7))*(5*sqrt(-2) + sqrt(7))and *** note well *** - this is a factorization in which everycoefcient in sight is an algebraic integer - just the kind of factorization that you wanted to get in the rst place, and the kind that you think cannot possibly be obtained. Clearly you are wrong. Believe what you see.>In this case the operation is division, and 7 *has* to have been>divided by 7, to give the result 1.> With the *correct* factorization, you dont get 1. You geta term which is non-coprime to 7. You are assuming that youmust get 1. That assumption is incorrect.>Now then, look *again* at what you said, and see if you can begin to>see differences in your claims about what I *thought* and my>explanation of what Ive said.> You assume - yes, ASSUME - that you *absolutely must* end up with1, 1, 22 after you have done the division. Conditional onthat, you would be right. That assumption however is false.Therefore your belief that the only reasonable factorizationof 49 is 7, 7, 1 is wrong. Yes, 7, 7, 1 is the only wayto end up with 1, 1, 22. But 1, 1, 22 is not the right goalin the rst place. There is no doubt however that you*think* it is. This is your whole basis for having said thata_1(x)/7 should be an algebraic integer.>> >Here youre caught, yet again, but rather than acknowledging the>obvious--you cant read minds--you instead toss out yet another>> >statement.>> > > > See above. That was a direct, unedited quote. I cant read>> > minds but I can read what you post. So can everyone else who>> > sees this.>> > Yup. Now then, look carefully back at what *you* said I thought, and>> Im curious to hear how you feel that the quote you gave is saying the>> same thing.>> Be quite detailed please.>> I said you thought that the only way to split 49 into three>> factors that would divide the three terms of>> (5 a_1(x) + 7)*(5 a_2(x) + 7)*(5 b_3(x) + 22)>> was as 49 = 7 * 7 * 1, where the rst 7 divides (5 a_1(x) + 7),>> the second 7 divides (5 a_2(x) + 7), and 1 divides (5 b_3(x) + 22).>> And indeed, that is precisely, exactly what you claimed.Nope. I talked about the *constant* terms in those factors, and noted>that those constant terms changed, and that there was only one way for>them to change.> What you noted however was wrong. There is another way forthem to change. You have just moved the error in your thinkingback about an inch. You thought the only factorization thathad any prayer of working at all would necessarily give you1, 1, 22 after division. That thought was incorrect. But still, you thought it. You were (and are) certain of it. And your (incorrect) certainty that 1, 1, 22 was necessary caused you to think that the only factorization of 49 that would work was 7, 7, 1. Anincorrect conclusion, but again: that is what you thought.>Even now you STILL dodge and twist to try and challenge the facts.Im being very specic here for a reason, but if you have>mathematical expertise then you should appreciate being VERY specic.Can you begin to see differences between what youre saying and what>Im saying?> I said you thought only one form of factorization waspossible. You have conrmed that totally. You haveleft no doubt about that whatsoever. You still think it.It is what has led you (misguidedly, and unnecessarily) to try to create your object ring. After all, your instinctthat there had to be some factorization which worked was,in fact, correct. Your belief that that factorization couldonly be of one form was not.>> If you now want to retract that, ne with me. That would>> open the door to other factorizations of 49 - for example>> 49 = w1(x)*w2(x)*w3(x), where w1(x), w2(x), and w3(x) are>> non-unit algebraic integers, and for x <> 0, none of them>> are equal to 7. If you are now willing to contemplate>> factorizations like that, rather than your inspection-based>> factorization 7, 7, 1, then your whole edice collapses.>> So, retract away!>>My position still remains that if you have *constants* 7, 7 and 22,>and then have 1, 1, and 22, after dividing by 49, its a matter of>simple arithmetic to determine what happened.> OK, ne, go back a step. Do you or do you not think that thatafter division by factors of 49, the constant terms MUST be transformedfrom 7, 7, 22 to 1, 1, 22 ? That no other end-result isconceivable? Be very careful in answering this. The big picture here is, you have made an erroneousassumption. Perhaps you are trying to salvage some scrapof pride. Forget it. Your assumptions - yes, ASSUMPTIONS -about what must happen after the division are wrong. Theyare based on the idea that after the divisions, theconstant terms must end up being algebraic integers.As outlined above and as absolutely proved by Rick Deckersexample, that ASSUMPTION is FALSE. That is your basicerror.>Now theres a difference between that and what youre claiming.> > >So I challenge you to give a single quote.>> > > > Done. See above. I await your explanation.>> > Its very simple. In fact, Ive been rather detailed about my>> factorization, and how it works.>> But you make statements that are attempts at trying to change the>> facts.>> Such as???Now you play dumb.> And you give no example.>> Like even though you gave that quote, you then didnt even bother to>> reconcile obvious differences!>> Like you have 7, 7, 1, while I talk of 7, 7 and 22.>> Oh, PLEASE!!! One of these is your proposed factorization>> of 49. The other is the constant terms of your factorization>> of P(x). If you think I have claimed they are the same, you>> are simply delusional. You clearly, unambiguously think, as you>> said in the quote, that the only way to factor 49 through the three>> linear factors of P(x) was as 7, 7, and 1. There is no doubtAnd now youre STILL trying to mindread. Now I didnt understand what>you meant by 7, 7 and 1 before, but now I do, A miracle. You actually read something and understood it. Praisethe Lord. Is there hope after all?>and it makes sense that>I didnt as I keep saying 7, 7 and 22 talking about the constant>terms.> You should read things with the idea that the personwriting them might have intended something other thanwhat you wanted to see.>As for your claim about ways to factor 49, thats just something>youre making up.> Ah, at last we get to the real heart of our disagreement! Therest actually is uff. This is the big sh. No, factors A, B, and C as described above actually exist. The proof is closely related to the Magidin-Mckinnon result. Dont believe it? Try producing a proof that it cant happen!And be sure - be very, very sure - that you arent assuming whatyou want to prove!>What I *say* is that the constant terms go from being 7, 7 and 22 to>being 1, 1, and 22, when 49 is divided off, which is an easily>veriable fact.> Not quite. You have to speak precisely here. It happens *only if* you factor 49 as 7, 7, 1. You can factor 49 in another way, as 49 = A*B*C. When you divide 7, 7, 22 by these, you do NOT get 1, 1, and 22. You get 7/A, 7/B, and 22/C. The former two are algebraic integers. 22/C is not. Try really, really hard to get this. The fact that 22/C is not an algebraic integer is not a problem. Remember, there are two ways to express that third factor: (5 b_3(x) + 22) = (5 a_3(x) + 7). It turns out that 7/C, like 7/A and 7/B, *is* an algebraic integer. So is a_3(x)/C, as well as a_1(x)/A and a_2(x)/B. Thus in 5 [a_3(x)/C] + 7/Call of the coefcients are algebraic integers. That is what you wereaiming for way back at the beginning. Remember? You havent lostsight of your goal, have you?>> Its something Ive watched before in your postings where you make>> little mistakes, big mistakes, and strange mistakes, but when its>> pointed out, you always deny!!!>> I ask of you what you asked of me: provide one example.>>My replies to your posts here are examining your behavior, so you need>only consult them.> Again I note a total absence of an example. Let me knowif youfind one.>> Later, I catch you making the *same* mistakes, and with VERY long>> posts, as if part of your strategy is burying your behavior with a lot>> of verbiage.>> This whole exchange is simply surreal. I make a statement about>> what you thought. You say I am falsely reading your mind. I>> provide a direct quote from 1 day before which proves 100% of>> what I said about your thinking. You squirm and turn and try>> to weasel out of it. You try to deny the meaning of your own>> quotation. WHO THE HELL ARE YOU TRYING TO FOOL, ANYWAY ?Im curious about how you go about what youre doing, to see if its>conscious, or unconscious as Im curious.> Whuh??? Can I quote you on that?>> Its kind of interesting behavior, though bizarre.>> >> >> Who cares what I think,>> >> >> >> You have made a huge error. My interest is in trying to>> >> get you to realize it.>> >> > >I dont think so. For instance, a while back in response to your>> > > > I will never, never engage in any nonpublic conversations with>> > you on any topic.>> So now you *nally* admit that you need an audience. Why do I have>> to drag the truth out of you?>> I dont want an audience. I want witnesses. I would never trust>> you to quote anything I said o'ne.How is that relevant to your claims about your purpose?> It wasnt supposed to be relevant. It was supposed to be an answer to your question.>Why dont you say what your purpose really is?> The best outcome I can imagine is that you nallysee why your reasoning on this whole thing is incorrect.I am none too optimistic about it.>> You make claims that dont t with your behavior.>> > >Now then, why dont you try again and explain what you *really* are>> >trying to do?>> > > > Its simple. I am trying to show you that your factorization of 49>> > in the 7, 7, 1 pattern is the WRONG FACTORIZATION when x <> 0. Needless>> > to say you are not getting it.>> Now theres one of the errors YET AGAIN, and I have to admit that its>> a puzzle to me.>> OK, I will say it as succinctly and clearly as I possibly can.>> You divide>> (5 a_1(x) + 7)*(5 a_2(x) + 7)*(5 b_3(x) + 22)>> by 49. You split 49 into 3 pieces: say, 49 = A*B*C.>> Your goal is for each of>> (5 a_1(x) + 7) / A,>> (5 a_2(x) + 7) / B, and>> (5 b_3(x) + 22) / C>> each to be algebraic integers.No. Thats not true. My point is that in generaly they are NOT>algebraic integers.> I know what your point is. Your point is wrong. If you picked A = 7, B = 7, and C = 1, you would be right. But it is possible to pickDIFFERENT A, B, and C so all the coefcients ARE algebraicintegers. A, B, and C are dependent on x. That is what Dik, Arturo, I, and others have been saying for months. Have you really not understood that?>Surely that should be something that you can now accept so that you no>longer say what you just did, right?That is, are you no longer going to claim that I say that after 49 is>divided off from both sides that you still have algebraic integers,>since Ive just told you explicitly thats not what Im saying?> You CAN divide 49 off from both sides so that you stillhave algebraic integers. You CANNOT do it by using 7, 7, 1.>> You say the ONLY POSSIBLE hope of achieving this is to>> specify:>> A = 7, B = 7, C = 1,>> because that is the only conguration that divides>> the constant terms as you want.>> We say NO. For one thing, as you now acknowledge,>> A = 7, B = 7, and C = 1 does NOT WORK in general:>> in particular,>> (5 a_1(x) + 7) / 7>> is NOT an algebraic integer for most x <> 0.>> You know this.Then why did you claim above that I make an opposite claim?> Jesus, you are either dumb as a post or at least illiterate.Cant you read the above ? Yes, you say that the only conceivableway to divide off 49 is by factoring it in the 7, 7, 1 pattern, andthen INDEED, the result if you do that is that the resulting coefcientsare not algebraic integers. I AGREE WITH THAT. Understand ?Please shake your head yes or no. Go back and read what you said. You said that dividing by 49 had to transform 7, 7, 22 into 1, 1, 22. You did not qualify how thatdivision by 49 might be done. You were thinking, though you did notsay it explicitly, that you were factoring 49 as 7*7*1. If you *had* said that, you would have been right technically (though totally wrong with respect to the big picture). But you CAN factor 49 as A*B*C with A, B, and C something other than 7, 7, 1 so that you DO get all algebraic integercoefcients. Again, if you want to see it done *explicitly* with allthe gory arithmetic details for a quadratic, see my post in the Rick Decker thread (quoted above also).>Can you see what Im seeing here? Is there any part of you that> acknowledges that, hey, other people reading might wonder whats going> on with you?> I am not concerned in the least about that socialstuff. Thats your concern. People can think about me whatever they want. Nora B.James Harris =Suppose f is a representation of the group G in the vector space V over k.Then f* is the representation of G in the dual vector space V* dened bythe action (gp)(v) = p((g^-1) v), where g is in G, p is in V*, and v is inV. (Firstly, why is this action dened like this?)Now suppose f is given in matrix form :f : g |--> A(g)where g is in G and A(g) denotes the matrix g is sent to.Then f* (the dual representation) is the representationg |---> (A(g)^{-1})^T, the transpose of the inverse of the matrix. Cansomeone tell me why the transpose of the inverse denes the dualrepresentation?Moshe Suppose f is a representation of the group G in the vector space V over k.> Then f* is the representation of G in the dual vector space V* dened by> the action (gp)(v) = p((g^-1) v), where g is in G, p is in V*, and v is in> V. (Firstly, why is this action dened like this?)> We have f:G->L(V), where L(V) denotes the linear operators on V. We dene f*:G->L(V*) so that = where = p(v) denes the duality between p in V* and v in V. This gives > Now suppose f is given in matrix form :> > f : g |--> A(g)> > where g is in G and A(g) denotes the matrix g is sent to.> > Then f* (the dual representation) is the representation> > g |---> (A(g)^{-1})^T, the transpose of the inverse of the matrix. Can> someone tell me why the transpose of the inverse denes the dual> representation?> = = .Substituting v->A(g)^{-1}v, we get = = (since for any matrix =). Since this is true for all v, we getgp = A(g)^{-1,T}p. Suppose f is a representation of the group G in the vector space V overk.> Then f* is the representation of G in the dual vector space V* denedby> the action (gp)(v) = p((g^-1) v), where g is in G, p is in V*, and v isin> V. (Firstly, why is this action dened like this?)> We have f:G->L(V), where L(V) denotes the linear operators on V. Wedene> f*:G->L(V*) so that> = = p(v) denes the duality between p in V* and v in V. ThisgivesWhy exactly do we want to dene f*:G->L(V*) so that = ? Whydoes this denition make sense? Is < > the standard inner product? Whatdo you mean by duality between p in V* and v in V?Moshe =Cutting Edge New Physics Ideas1. Dark energy is almost 2/3 of the Universe and is a repelling anti-gravity eld.2. Dark matter is almost 1/3 of the Universe and is an attractive us are made of.3. Ordinary matter and light is only a very tiny part of the Universe.4. Put a chunk of dark energy near a chunk of dark matter and you basically have a weightless warp drive. This means you feel weightless and the Universe passes by you seemingly faster than the speed of light. You can time travel to your past and to your future and beyond under certain conditions.5. Einsteins theory of special relativity from 1905 is the unication of space with time into a rigid space-time and the unication of matter and energy.6. Einsteins general theory of relativity shows that space-time is not rigid but is warped not only by energy but also even by itself in a self-organizing way.7. Quantum theory is about the informational relationship between the observer and the observed. Some important physicists like John Von Neumann, Eugene Wigner and Roger Penrose thought that our inner consciousness plays a key role in quantum physics. Other important physicists violently disagree. It depends what you mean by quantum theory. There are many different ways of interpreting it and its boundary of validity is not yet understood especially in the strong gravity eld of a black hole. A key issue is signal nonlocality, i.e. the use of entanglement as a direct communication channel without an auxiliary light speed limited classical channel as in quantum teleportation and cryptography where Eve cannot tap the channel between Alice and Bob without them knowing it. These applications require irreducible quantum randomness that is thought to forbid signal nonlocality, i.e. to enforce signal locality or passion at a distance (Abner Shimony). On the other hand see http://www.quantumelds.com/469Maclay.pdf The analysis of Lenny Susskind, for example, of information loss behind the event horizon of a black hole, depends on signal locality as does the non-Boolean toposquantum logic of cosmology mentioned by Lee Smolin. Yet, the Bohmian analysis of Antony Valentini suggests otherwise. The idea here is that orthodox nonlocal micro-quantum theory with irreducible randomness and consequent signal locality is only the sub-quantal thermal equilibrium limit of a more general non-equilibrium local MACRO-QUANTUM theory for cosmology and the emergence of classical curved space-time with signal nonlocality.http://qedcorp.com/APS/EmergentGravity.pdf8. The which has two main schools of thought, string theory and loop theory. The two theories may simply be dual dimensional images of each other. The basic object of loop theory is a two-dimensional undivided quantum of area and the basic object of string theory is a one-dimensional undivided quantum of length, which together make a three-dimensional space. Loop theory describes three-dimensional space as zero-dimensional point on a kind of quantum computing spin network. When you add a kind of proto time to it you get a spin foam. Two-dimensional area is described by a 1-dimensional stringy edge on the spin network. The duality is intuitively obvious. The 1-dimensional physical string is really like a linked chain with each link as a bit of information not unlike the purely mathematical strings of computer theory. No matter that the string is embedded in a higher dimensional hyperspace since all but three of those extra spacelike dimensions are curled up into tiny circles with radii called moduli forming what the mathematicians like to call a Calabi-Yau space. Brian Greene calls this an Elegant Universe in which the spin foam is weaved into the fabric of reality. God is seen by Brian as a kind of tailor or fashion designer reminding me of the Vatican scene in Fellinis Roma.9. Both the string and the loop theorists think that the quanta of length and area respectively are always very tiny. They may be mistaken in this belief. Then again, I may be mistaken. Cutting Edge New Physics Ideas 1. .8bDark energy.8a is almost 2/3 of the Universe and is a repelling> anti-gravity eld. 2. .8bDark matter is almost 1/3 of the Universe and is an attractive> us are made of.It would seem hard to believe that Dark Matter stays so perfectly separatedfrom the rest of matter. Youd think some of this stuff would come oatinginto the regions of the universe where the rest of us live too.Another possibility put forth is the Modied Newtonian Dynamics (MOND),where gravitational attraction take on new equational forms depending on thedistance of measurement from centre of mass to centre of mass, over greatdistances.> 3. Ordinary matter and light is only a very tiny part of the Universe. 4. Put a chunk of dark energy near a chunk of dark matter and you> basically have a weightless warp drive. This means you feel weightless> and the Universe passes by you seemingly faster than the speed of light.> You can time travel to your past and to your future and beyond under> certain conditions.Its a possibility, except that dark energy seems to only take effect onceyou have sufcient distance. Like the distances between galactic clusters.And actually I wonder if this isnt also another boundary condition of MOND,where the equations of gravity actually turn it into a repelling force? Yousuf Khan 4. Put a chunk of dark energy near a chunk of dark matter and you > basically have a weightless warp drive. This means you feel weightless > and the Universe passes by you seemingly faster than the speed of light. > You can time travel to your past and to your future and beyond under > certain conditions.Why havent we been visited by future folk? Tha have had eternity to develop this idea.Bob Kolker > 4. Put a chunk of dark energy near a chunk of dark matter and you >> basically have a weightless warp drive. This means you feel weightless >> and the Universe passes by you seemingly faster than the speed of >> light. You can time travel to your past and to your future and beyond >> under certain conditions.> Why havent we been visited by future folk? Tha have had eternity to > develop this idea.> Bob KolkerDoubtless were quite boring by comparison. > Doubtless were quite boring by comparison.Maybe they visited Jack and did not let the rest of us know about it.Bob Kolker > > Doubtless were quite boring by comparison.> Maybe they visited Jack and did not let the rest of us know about it.That *would* likely do it. Cutting Edge New Physics Ideas 4. Put a chunk of dark energy near a chunk of dark matter and you> basically have a weightless warp drive. This means you feel weightless> and the Universe passes by you seemingly faster than the speed of light.> You can time travel to your past and to your future and beyond under> certain conditions.>Oh yeah, that makes a lot of sense. LMAO. Cutting Edge New Physics Ideas 4. Put a chunk of dark energy near a chunk of dark matter and you> basically have a weightless warp drive. This means you feel weightless> and the Universe passes by you seemingly faster than the speed of light.> You can time travel to your past and to your future and beyond under> certain conditions. > > > > Oh yeah, that makes a lot of sense. LMAO.[EL]Jack Sarfatti is not insane at all.He is the ultimate of the 20th Century knowledgeable Physicist andwhat makes you laugh your ass out is not Jacks insanity, but theinsanity of mainstream physics, which Jack have mastered to a level ofdivinity.accepted widely by the physics community including the darkness ofenergy and matter along with holes that have a black colour and bangsthat are big when size did not even make any sense. Not to mentiontime that became a street in which Minkowski played hide and seek withEinstein going to and fro while the twin was getting younger.Wait until Jack tells you about the quarks with its pink colour andvanilla avour not only going up and down but dancing jerk andpsychedelic while occasionally doing the samba and the rumba. It isall in the bubble chamber with empirical evidence and pictures ofsophisticated kids interpreting the maps made by chicken nails feedingin a barn on special plastic that records the trails scratching thesurfaces.We are living in a fabulous zoo so come and watch the humans.Jack is an idol that represents this Century.He is a physics showman.Refuting him is futile and I suggest that you go back to your bakeryand bake some more bread before your kids get hungry. Leave thedreamers dream but give them no bread and they shall be excludedevolutionary wise.EL =Example:I am a researcher. I study UFOs and ghosts.I have determined that %77 of all ghosts are spotted within a 5 mile radiusof UFO sightings, and that %82 of all UFO sightings are accompanied by ageneral increase in the intensity and overall magnitude of ghost relatedhauntings.Therefore, I conclude, via statistics, that ghosts and UFOs are somehowrelated, and that ghosts are in all probability using UFOs fortransportation purposes.-----------------------------------------------Will someone in the sci.math or sci.math.stat please stand up and tell mewhy this is awed, and no I am not kidding. I need an independent opinion.People are telling me Im crazy - where did I go wrong ????? Can I call thisscience ?? Is my reasoning awed somehow ?? Is there a problem with mypopulations - or is this valid usage of stats ?? Example:> > I am a researcher. I study UFOs and ghosts.> > I have determined that %77 of all ghosts are spotted within a 5 mile radius> of UFO sightings, and that %82 of all UFO sightings are accompanied by a> general increase in the intensity and overall magnitude of ghost related> hauntings. Therefore, I conclude, via statistics, that ghosts and UFOs are somehow> related, and that ghosts are in all probability using UFOs for> transportation purposes.> > -----------------------------------------------> > Will someone in the sci.math or sci.math.stat please stand up and tell me> why this is awed, and no I am not kidding. I need an independent opinion.> > People are telling me Im crazy - where did I go wrong ????? Can I call this> science ?? Is my reasoning awed somehow ?? Is there a problem with my> populations - or is this valid usage of stats ??> > > > > Is there some ofcially recognized listing of ghost sightings andUFO sightings? If not, theres always GIGO to explain it. Example: I am a researcher. I study UFOs and ghosts. I have determined that %77 of all ghosts are spotted within a 5 mileradius> of UFO sightings, and that %82 of all UFO sightings are accompanied by a> general increase in the intensity and overall magnitude of ghost related> hauntings. Therefore, I conclude, via statistics, that ghosts and UFOs are somehow> related, and that ghosts are in all probability using UFOs for> transportation purposes. ----------------------------------------------- Will someone in the sci.math or sci.math.stat please stand up and tellme> why this is awed, and no I am not kidding. I need an independentopinion. People are telling me Im crazy - where did I go wrong ????? Can I callthis> science ?? Is my reasoning awed somehow ?? Is there a problem withmy> populations - or is this valid usage of stats ??> Is there some ofcially recognized listing of ghost sightings and> UFO sightings? If not, theres always GIGO to explain it.You are getting warmer !!! You are very close to the fallacy Im lookingfor. You have almost nailed it.Just one hint -In statistics, the populations and samples are EXTREMELY important. Forinstance, all of your work is invalidated if your populations are messed up.Does anyone see a problem with sha1:cUhzCUd56pq9NqbQ5oqOiDpsjYQ => Is there some ofcially recognized listing of ghost sightings and>> UFO sightings? If not, theres always GIGO to explain it. You are getting warmer !!! You are very close to the fallacy Im looking> for. You have almost nailed it. Just one hint -> In statistics, the populations and samples are EXTREMELY important. For> instance, all of your work is invalidated if your populations are messed up. Does anyone see a problem with my scientic population of ghosts and> UFOs ?Theres no such thing as ghosts or UFOs? :) = >> Is there some ofcially recognized listing of ghost sightings and>> UFO sightings? If not, theres always GIGO to explain it. You are getting warmer !!! You are very close to the fallacy Im looking> for. You have almost nailed it. Just one hint -> In statistics, the populations and samples are EXTREMELY important. For> instance, all of your work is invalidated if your populations are messedup. Does anyone see a problem with my scientic population of ghosts and> UFOs ? Theres no such thing as ghosts or UFOs? :)YES !! Excellent, and now we are getting somewhere !!So, while it is technically possible that UFOs and gosts really exist, Icannot claim that any related analysis of the subject is actually validuntil I can prove that these questionable things really do exist.If I am a scientist, and I spend the next 40 years using the entirety of thebody of all statistical methods to analyze ghosts and UFOs, even if I didall the math correctly, my so-called science is still just garbage becauseI cannot prove that UFOs and ghosts even exist !!Now we are getting somewhere !!If anyone else is wliling to conrm what I am saying - please just jumpright in. If I am just dead wrong please post as well. Whatever. Lets hearit. = Toilet Seat .8d.98.87.8b.8c .97.99.95 scientic population of ghostsand> > UFOs ? Theres no such thing as ghosts or UFOs? :) YES !! Excellent, and now we are getting somewhere !! So, while it is technically possible that UFOs and gosts really exist,I> cannot claim that any related analysis of the subject is actually valid> until I can prove that these questionable things really do exist. If I am a scientist, and I spend the next 40 years using the entirety ofthe> body of all statistical methods to analyze ghosts and UFOs, even if I did> all the math correctly, my so-called science is still just garbagebecause> I cannot prove that UFOs and ghosts even exist !! Now we are getting somewhere !! If anyone else is wliling to conrm what I am saying - please just jump> right in. If I am just dead wrong please post as well. Whatever. Letshear> it.Well, there are extant possibilities here, I ll admit, although some appearto be out of the ordinary.In principle, you *could* perform several interesting scientic tests,based only on the loose assumption that some people believe in such things.Years ago, for example, I remember Bud Hopkins, who was AFAIR WhitleyStreibers psychologist, perform several statistical tests on supposedabductees, and then announcing some results on some of his books.The results claimed that the phenomenon of UFOs, appears to be some sort ofvery particular psychological event, linked to not any specic traumaresulting from childhood, rather to sociological factors having a lot to dowith religious tradition and brainswashing.Specic instances of apparitions (such as that of the Lady of Fatima) andvarious locales where ghosts supposedly appear, (such as in England), seemto be related to some extent to these phenomena, but for me, only in asocioanthropological way, with no scientic support base underneeth. Atleast not a *provable* scientic basis.To that extent, you could try to scientically investigate WHY some peoplesee ghosts and UFOs and seriously try to deduce some sort of correlationbetween their previous mental states, their religious states or theirsocial/religious background, as individuals or as nations (who often carrywith them severely absurd traditions).I presume that in such a case youd probably need to study a lot ofpsychology rst.As an amateur astronomer, myself, have been scanning the heavens since I was12, with both binoculars and telescopes. Ive seen nothing so far thatindicates the presence of UFOs.On the other hand, as a person with some deep traumas from childhoodresulting from various factors, I am convinced that somebodys pulling somevery weird tricks on us. Who is that? I have no idea.--Ioannis Galidakishttp://users.forthnet.gr/ath/jgal/------------------ ------------------------Eventually, _everything_ is understandable .93 Toilet Seat [NonBreakingSpace].8b.96.87.8c .97.99.95 problem with my scientic population of ghosts> and> > UFOs ?> > Theres no such thing as ghosts or UFOs? :) YES !! Excellent, and now we are getting somewhere !! So, while it is technically possible that UFOs and gosts reallyexist,> I> cannot claim that any related analysis of the subject is actually valid> until I can prove that these questionable things really do exist. If I am a scientist, and I spend the next 40 years using the entirety of> the> body of all statistical methods to analyze ghosts and UFOs, even if Idid> all the math correctly, my so-called science is still just garbage> because> I cannot prove that UFOs and ghosts even exist !! Now we are getting somewhere !! If anyone else is wliling to conrm what I am saying - please just jump> right in. If I am just dead wrong please post as well. Whatever. Lets> hear> it. Well, there are extant possibilities here, I ll admit, although someappear> to be out of the ordinary. In principle, you *could* perform several interesting scientic tests,> based only on the loose assumption that some people believe in suchthings.> Years ago, for example, I remember Bud Hopkins, who was AFAIR Whitley> Streibers psychologist, perform several statistical tests on supposed> abductees, and then announcing some results on some of his books. The results claimed that the phenomenon of UFOs, appears to be some sortof> very particular psychological event, linked to not any specic trauma> resulting from childhood, rather to sociological factors having a lot todo> with religious tradition and brainswashing. Specic instances of apparitions (such as that of the Lady of Fatima) and> various locales where ghosts supposedly appear, (such as in England), seem> to be related to some extent to these phenomena, but for me, only in a> socioanthropological way, with no scientic support base underneeth. At> least not a *provable* scientic basis. To that extent, you could try to scientically investigate WHY somepeople> see ghosts and UFOs and seriously try to deduce some sort of correlation> between their previous mental states, their religious states or their> social/religious background, as individuals or as nations (who often carry> with them severely absurd traditions). I presume that in such a case youd probably need to study a lot of> psychology rst. As an amateur astronomer, myself, have been scanning the heavens since Iwas> 12, with both binoculars and telescopes. Ive seen nothing so far that> indicates the presence of UFOs. On the other hand, as a person with some deep traumas from childhood> resulting from various factors, I am convinced that somebodys pullingsome> very weird tricks on us. Who is that? I have no idea.> --> Ioannis Galidakis> http://users.forthnet.gr/ath/jgal/> ------------------------------------------> Eventually, _everything_ is understandable>So then, you are saying that I can enter Bigoot into a book on anthropology? I can submit Wolfman to the eld of biology ? I can count upon theinvisible man as being a fact of physics ?Are you indeed suggesting that valid science might be conducted upon anactual UFO - something which no-one has ever proved to exist ??Are you saying that you can perform real science upon a ghost ? Again -something which has never been proven to exist ?? Can you give it a physical? = Toilet Seat .8d.98.87.8b.8c .97.99.95 enter Bigoot into a book onanthropology> ? I can submit Wolfman to the eld of biology ? I can count upon the> invisible man as being a fact of physics ? Are you indeed suggesting that valid science might be conducted upon an> actual UFO - something which no-one has ever proved to exist ?? Are you saying that you can perform real science upon a ghost ? Again -> something which has never been proven to exist ?? Can you give it aphysical> ?None of that. All I am saying is that you can do valid science with thepeople who CLAIM to have seen such things. Grab a population, listen to whatthey are saying, study your data and correlate this with their backgroundand ethnicity.Then draw your conclusions. Not conclusions on whether UFOs or ghostsexist, rather what is it that makes those people who believe in them, tick.--Ioannis Galidakishttp://users.forthnet.gr/ath/jgal/------------------ ------------------------Eventually, _everything_ is understandable .93 Toilet Seat [NonBreakingSpace].8b.96.87.8c .97.99.95 that I can enter Bigoot into a book on> anthropology> ? I can submit Wolfman to the eld of biology ? I can count upon the> invisible man as being a fact of physics ? Are you indeed suggesting that valid science might be conducted uponan> actual UFO - something which no-one has ever proved to exist ?? Are you saying that you can perform real science upon a ghost ? Again -> something which has never been proven to exist ?? Can you give it a> physical> ? None of that. All I am saying is that you can do valid science with the> people who CLAIM to have seen such things. Grab a population, listen towhat> they are saying, study your data and correlate this with their background> and ethnicity. Then draw your conclusions. Not conclusions on whether UFOs or ghosts> exist, rather what is it that makes those people who believe in them,tick.> --> Ioannis GalidakisExcellent work Ioannis, thank you for your thoughful response. I agree withyou %100. It is possible to statistics on what people claim to have seen,or what they claim to believe, etc etc.It is possible to do science upon claims.But even though millions of people claim to believe in God, we are unable todo real science upon God directly - for example. We can analyze theirclaims scientically, but cannot really study God himself by thisprocess.Would you agree with this ? = Toilet Seat .8d.98.87.8b.8c .97.99.95 for your thoughful response. I agreewith> you %100. It is possible to statistics on what people claim to haveseen,> or what they claim to believe, etc etc. It is possible to do science upon claims. But even though millions of people claim to believe in God, we are unableto> do real science upon God directly - for example. We can analyze their> claims scientically, but cannot really study God himself by this> process. Would you agree with this ?Hmmmm... Lets see: The objects you mention (i.e. God, ghosts, UFOs) areintangible. As such they appear as though they cannot offer themselves asvalid objects for a scientic study, as you say.One has to be careful tho. Abstract mathematics deals with objects which areintangible, also.So now I will reverse the question for you:1) God is an intangible object, as such one cannot study itscientically.2) Natural numbers are intangible objects, as such one cannot study themscientically.2) is plainly false, since Abstract Mathematics is a plenty valid scienticdiscourse.What is it that differentiates those two classes of intangible objects,say: {God, UFOs, ghosts} vs {x:x = Some abstract Mathematical construct}and makes one class a valid scientic discourse while makes the other adiscourse in nonsense?Your answer, (i.e. the answer to your original question), lies inpinpointing the exact difference between the two example classes, above. :*)--Ioannis Galidakishttp://users.forthnet.gr/ath/jgal/------------------ ------------------------Eventually, _everything_ is understandable .93 Toilet Seat [NonBreakingSpace].8b.96.87.8c .97.99.95 Ioannis, thank you for your thoughful response. I agree> with> you %100. It is possible to statistics on what people claim to have> seen,> or what they claim to believe, etc etc. It is possible to do science upon claims. But even though millions of people claim to believe in God, we areunable> to> do real science upon God directly - for example. We can analyze their> claims scientically, but cannot really study God himself by this> process. Would you agree with this ? Hmmmm... Lets see: The objects you mention (i.e. God, ghosts, UFOs)are> intangible. As such they appear as though they cannot offer themselves as> valid objects for a scientic study, as you say. One has to be careful tho. Abstract mathematics deals with objects whichare> intangible, also. So now I will reverse the question for you: 1) God is an intangible object, as such one cannot study it> scientically.> 2) Natural numbers are intangible objects, as such one cannot study them> scientically. 2) is plainly false, since Abstract Mathematics is a plenty validscientic> discourse. What is it that differentiates those two classes of intangible objects,> say: {God, UFOs, ghosts} vs {x:x = Some abstract Mathematical construct}> and makes one class a valid scientic discourse while makes the other a> discourse in nonsense? Your answer, (i.e. the answer to your original question), lies in> pinpointing the exact difference between the two example classes, above.:*)> --> Ioannis Galidakis> http://users.forthnet.gr/ath/jgal/> ------------------------------------------> Eventually, _everything_ is understandable>The distinction is that mathematics deals with abstractions.These other items such as God, Angels, Luck, Fate, and probably most humanemotions are considered metaphysical.Mathematical abstractions are certainly measurable. Also - if you constructabstract entities such as abstract joy, then you could concievably measureor quantify joy. But, you cannot measure real human levels of joy, just asit is bogus to attempt to measure intelligence, or love, etc. > Example:> > I am a researcher. I study UFOs and ghosts.> > I have determined that %77 of all ghosts are spotted within a 5 mile> radius> > of UFO sightings, and that %82 of all UFO sightings are accompanied bya> > general increase in the intensity and overall magnitude of ghostrelated> > hauntings.> > Therefore, I conclude, via statistics, that ghosts and UFOs aresomehow related, and that ghosts are in all probability using UFOs for> > transportation purposes.> > -----------------------------------------------> > Will someone in the sci.math or sci.math.stat please stand up andtell> me> > why this is awed, and no I am not kidding. I need an independent> opinion.> > People are telling me Im crazy - where did I go wrong ????? Can Icall> this> > science ?? Is my reasoning awed somehow ?? Is there a problem with> my> > populations - or is this valid usage of stats ??> > Is there some ofcially recognized listing of ghost sightings and> UFO sightings? If not, theres always GIGO to explain it. You are getting warmer !!! You are very close to the fallacy Im looking> for. You have almost nailed it. Just one hint -> In statistics, the populations and samples are EXTREMELY important. For> instance, all of your work is invalidated if your populations are messedup. Does anyone see a problem with my scientic population of ghosts and> UFOs ?Is there nobody who will ask me to PROVE that I have isolated and identiedsuch populations ?? Seriously folks - or can I just take my data and waltzover to the National Academy of Science and expect to get my research funded?Should I be expected to demonstrate the existence of UFOs and ghosts tobe considered solid science - or, are we now accepting pyramid power andcold fusion as a means of reducing fossil fuel consumption ???Someone please tell me that Im not hallucinating - please conrm -independently - that for science to be VALID, that populations in statisticsshould be either veriable, reproducible, falsiable, or provable. Or wasmy 8th grade science teacher just lying to me about all that stuff ?If anyone can answer - please post !!! > > Example:>> > > I am a researcher. I study UFOs and ghosts.>> > > I have determined that %77 of all ghosts are spotted within a 5 mile>> radius>> > of UFO sightings, and that %82 of all UFO sightings are accompanied by>a>> > general increase in the intensity and overall magnitude of ghost>related>> > hauntings.>> > > Therefore, I conclude, via statistics, that ghosts and UFOs are>somehow> related, and that ghosts are in all probability using UFOs for>> > transportation purposes.>> > > ----------------------------------------------->> > > Will someone in the sci.math or sci.math.stat please stand up and>tell>> me>> > why this is awed, and no I am not kidding. I need an independent>> opinion.>> > > People are telling me Im crazy - where did I go wrong ????? Can I>call>> this>> > science ?? Is my reasoning awed somehow ?? Is there a problem with>> my>> > populations - or is this valid usage of stats ??>> > > > > > Is there some ofcially recognized listing of ghost sightings and>> UFO sightings? If not, theres always GIGO to explain it.>> You are getting warmer !!! You are very close to the fallacy Im looking>> for. You have almost nailed it.>> Just one hint ->> In statistics, the populations and samples are EXTREMELY important. For>> instance, all of your work is invalidated if your populations are messed>up.>> Does anyone see a problem with my scientic population of ghosts and>> UFOs ?Is there nobody who will ask me to PROVE that I have isolated and identied>such populations ??Dont know about other newsgroups, but Im answering from sci.math.> Seriously folks - or can I just take my data and waltz>over to the National Academy of Science and expect to get my research funded>?No, because at that stage, you will be asked also about yourmethodology for collecting data. But you asked for help from sci.math,so your request was understood in the terms of mathematics, not in theterms of empirical science research. You wanted people to fault yourassumptions, not your method for deriving conclusions? Then you did apoor job of presenting the problem for a mathematician.To this mathematician, your request could be paraphrased as follows: Assume that I have determined that 77% of all ghosts sightings occur within a 5 mile radius of a UFO sighting, and that 82% of all UFO sightings are accompanied by an increase in the intensity and magnitude of ghost-related-haunting-reports. related; I also conclude that ghosts are in all probability, using UFOs for transportations. Does the conclusion follow from the assumptions?analysis, the former (validity of assumptions) is irrelevant. We areonly seeing whether or not you are correctly interpreting thestatistics, not whether the statistics are correct-- ==Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) > Example:>> > > I am a researcher. I study UFOs and ghosts.>> > > I have determined that %77 of all ghosts are spotted within a 5mile>> radius>> > of UFO sightings, and that %82 of all UFO sightings are accompaniedby>a>> > general increase in the intensity and overall magnitude of ghost>related>> > hauntings.>> > > Therefore, I conclude, via statistics, that ghosts and UFOs are>somehow>> > related, and that ghosts are in all probability using UFOs for>> > transportation purposes.>> > > ----------------------------------------------->> > > Will someone in the sci.math or sci.math.stat please stand up and>tell>> me>> > why this is awed, and no I am not kidding. I need an independent>> opinion.>> > > People are telling me Im crazy - where did I go wrong ????? Can I>call>> this>> > science ?? Is my reasoning awed somehow ?? Is there a problemwith>> my>> > populations - or is this valid usage of stats ??>> > > > > > Is there some ofcially recognized listing of ghost sightings and>> UFO sightings? If not, theres always GIGO to explain it.>> You are getting warmer !!! You are very close to the fallacy Imlooking>> for. You have almost nailed it.>> Just one hint ->> In statistics, the populations and samples are EXTREMELY important. For>> instance, all of your work is invalidated if your populations aremessed>up.>> Does anyone see a problem with my scientic population of ghosts and>> UFOs ?Is there nobody who will ask me to PROVE that I have isolated andidentied>such populations ?? Dont know about other newsgroups, but Im answering from sci.math. presented your conclusions. As a mathematician, if somebody asks me to> check something like that, I would take the assumptions as granted,> and investigate, rather, whether the conclusions actually follow from> the assumptions. Whether or not the assumptions actually hold is a> separate issue, and usually of only secondary interest. The same would> be true for statistics: you presented statistics, and conclusions> derived from them. It is likely people interpreted your request as> asking whether or not your conclusion would indeed follow from such> statistics, NOT whether the statistics were accurate.Indeed - my example was poorly worded, perhaps somewhat sarcasticly in anattempt to provide a little humor or levity to the sillyness of this.And, indeed, I certainly could have worded it more formally, and I thank youfor pointing that out.> Seriously folks - or can I just take my data and waltz>over to the National Academy of Science and expect to get my researchfunded>? No, because at that stage, you will be asked also about your> methodology for collecting data. But you asked for help from sci.math,> so your request was understood in the terms of mathematics, not in the> terms of empirical science research. You wanted people to fault your> assumptions, not your method for deriving conclusions? Then you did a> poor job of presenting the problem for a mathematician.Both are at fault here, and if there were some way to distinguish one asbeing more faulty than the other I would like to see that. However, based onmy sensate human experiences in this world, Ifind it absolutely andpatently absurd in the extreme to say the least, that someone could claim tohave collected data about things like bigfoot, UFOs, alien abductions,Wolfman (for es g), when it is rather obvious that these items cannot bestudied due to their failure to even exist.> To this mathematician, your request could be paraphrased as follows: Assume that I have determined that 77% of all ghosts sightings occur> within a 5 mile radius of a UFO sighting, and that 82% of all UFO> sightings are accompanied by an increase in the intensity and> magnitude of ghost-related-haunting-reports. related; I also conclude that ghosts are in all probability, using> UFOs for transportations.Well, a correct wording that I was actually after would require existence ofghosts of UFOs or aliens etc. Your rewording provides for sightings -which can clearly exist, because people can be wrong.If I had an opportunity to reword part of this in such a way which wouldrequire the existence of the subject, please allow me the opportunity - forex, I have determined that %77 of all ghosts are located within a 5 mileradius of UFO landing sites. Furthermore, %82 of all UFO landings and alienvisitations are located within 8 miles of a ghost.Now, in this rewording there is no ambiguity - I have asserted indirectlythat I know where the ghosts are , and that I have found aliens, etc. For mystatements to be true, aliens must exist, and ghosts must exist, and Ishould be able to prove it or be called a quack.> Does the conclusion follow from the assumptions?You are correct - it does not, nor did it in the original post. No problem.> view of pure logic, it is immaterial whether or not the assumptions> are valid. The only question is whether or not the conclusions follow> from the assumptions, and they do not.This is true. But it _is_ within the purview of statistics to invalidate aconclusion or result when the initial sets upon which the analysis isperformed are found to be corrupted.Suppose, for example, that I published information regarding the averageheight, weight and IQ of a sample population of ghosts, and I made the claimthat the average IQ was higher and standard deviation was exactly 1/2 of asimilar sized sample from a population of angels.You dont have a problem with that ? If this turned up in the MAA MathMagazine or somewhere, and it was presented as factual data - you aretelling me that you would not question how I took the samples ? Where Ifound such populations in the rst place ?> The fact that your assumptions are, in fact, false, damns your> premises; the fact that your conclusions do not follow from your> premises (via statistics or not) damns your analysis of those> assumptions.OK -> ->EITHER<- of those two faults makes your report useless as science> Both together make it doubly useless as science. As statistical> analysis, the former (validity of assumptions) is irrelevant. We are> only seeing whether or not you are correctly interpreting the> statistics, not whether the statistics are correctYou have done a very careful and thorough job of correcting me and I am mostappreciative that you would take this seriously - but we are getting furtherfrom my objective.Without rewriting the question, or rewording the statement, I give you myclaim. I claim that if you do statistics on ivalid data, then your results areinvalid by denition, regardless of whether the derived solutions comeout correct or not.> == = Its not denial. Im just very selective about> what I accept as reality.> --- Calvin (Calvin and Hobbes)> == == Arturo Magidin> magidin@math.berkeley.edu> [.snip.]>Well, a correct wording that I was actually after would require existence of>ghosts of UFOs or aliens etc. Your rewording provides for sightings ->which can clearly exist, because people can be wrong.Just a short point here: in your original post, there were four thingsmentioned: ghosts spotted, UFO sightings, UFO sightings, ghostrelated haunting; only the latter talks about actual phenomena, whilethe former three are readily interpreted as reports of sightings. [.snip.]> view of pure logic, it is immaterial whether or not the assumptions>> are valid. The only question is whether or not the conclusions follow>> from the assumptions, and they do not.>This is true. But it _is_ within the purview of statistics to invalidate a>conclusion or result when the initial sets upon which the analysis is>performed are found to be corrupted.You are confusing validity with soundness, I think. Like I said, mostpeople in sci.math seem to have interpreted your question as aquestion about validity, when you are clearly more interested insoundness. >Suppose, for example, that I published information regarding the average>height, weight and IQ of a sample population of ghosts, and I made the claim>that the average IQ was higher and standard deviation was exactly 1/2 of a>similar sized sample from a population of angels.You dont have a problem with that ? Yes, I might have a problem with that.>If this turned up in the MAA Math>Magazine or somewhere, and it was presented as factual data - you are>telling me that you would not question how I took the samples ? Where I>found such populations in the rst place ?there would be no reason for it to be in the Mathematics Magazine(which, by the way, a journal for expository undergraduate levelmathematics; but I assume you mean a mathematical peer reviewedjournal on statistics or some such); and (b) the process whereby thedata was supposedly acquired would have to be included; thatsexperiment design.correlation calculation, then I wouldnt care: it would be a made-upexample to highlight certain ->mathematical features<- of the models,not a discussion of actual fact.>Without rewriting the question, or rewording the statement, I give you my>claim.> I claim that if you do statistics on ivalid data, then your results are>invalid by denition, regardless of whether the derived solutions come>out correct or not.Again, I think you are confusing soundness with validity.The validity of an argument refers to whether the conclusions followfrom the premises; an argument is valid if and only if they do.On the other hand, an argument is ->sound<- if and only if, inaddition to being valid, the premises hold. So what you shoudl really say is that if you do statistics frominvalid data, then your argument is necessarily ->UNSOUND<-. (Of course, to further claim that the conclusions of an unsoundargument must be false is itself a logical fallacy, called anArgumentum ad logicam)Mathematics (and statistical analysis as such) are concerned rst andforemost with validity, not with soundness. Of course, statisticalanalysis is seldom used as an intellectual exercise, and is insteadembedded inside a process that requires a test of soundness inaddition to validity, which is I think what you are concerned about.There is in fact a famous aphorism by Bertrand Russell: Mathematicsmay be dened as the subject in which we never know what we aretalking about, nor whether what we are saying is true. Because wecare about whether the argument is valid, but not whether it is sound,or what the premises are to be applied to.So, when you came to sci.math and sci.math.stat, your questions wasinterpreted as a question on validity; but you are obviously far moreinterested in soundness than in validity. It is certainly not a badidea to check on the truth of the premises before starting analysis-- == ==Its not denial. Im just very selective about what I accept as reality. --- Calvin (Calvin and Hobbes) So what you shoudl really say is that if you do statistics from> invalid data, then your argument is necessarily ->UNSOUND<-.was originally attempting to communicate, albeit somewhat sinically.I always learn so much from you guys - every time I shop for knowledge -your appreciation for == I have determined that %77 of all ghosts are spotted within a 5> mile radius of UFO sightings, and that %82 of all UFO sightings> are accompanied by a general increase in the intensity and> overall magnitude of ghost related hauntings. Is there nobody who will ask me to PROVE that I have isolated and> identied such populations??Not when youve assumed the above for the purpose of discussion.> Seriously folks - or can I just take my data and waltz over to the> National Academy of Science and expect to get my research funded ?Your question on sci.math is about the interpretation of statisitcs.That you also made up your numbers is not an interesting issue,mathematically.> Someone please tell me that Im not hallucinating - please conrm -> independently - that for science to be VALID, that populations in> statistics should be either veriable, reproducible, falsiable,> or provable.The population of people claiming to have spotted a UFO is as goodas any other. If you had actually surveyed them, rather than making upyour numbers, then there would be no quibble with the result: thequibble would be whether you recognized that it was a fact aboutclaimants, or misrepresented it as a fact about UFOs.Len. == I have determined that %77 of all ghosts are spotted within a 5 mile> radius of UFO sightings, and that %82 of all UFO sightings are> accompanied by a general increase in the intensity and overall> magnitude of ghost related hauntings. Therefore, I conclude, via statistics, that ghosts and UFOs are somehow> related, and that ghosts are in all probability using UFOs for> transportation purposes. Will someone in the sci.math or sci.math.stat please stand up and> tell me why this is awed, and no I am not kidding. I need an> independent opinion.You are confused as to what you are studying. The correct conclusionis that CLAIMED SIGHTINGS of UFOs correlate with CLAIMED SIGHTINGS ofghosts. You are not studying UFOs or ghosts, but claims concerningthem.Len. = I have determined that %77 of all ghosts are spotted within a 5 mile> radius of UFO sightings, and that %82 of all UFO sightings are> accompanied by a general increase in the intensity and overall> magnitude of ghost related hauntings. Therefore, I conclude, via statistics, that ghosts and UFOs are somehow> related, and that ghosts are in all probability using UFOs for> transportation purposes. Will someone in the sci.math or sci.math.stat please stand up and> tell me why this is awed, and no I am not kidding. I need an> independent opinion. You are confused as to what you are studying. The correct conclusion> is that CLAIMED SIGHTINGS of UFOs correlate with CLAIMED SIGHTINGS of> ghosts. You are not studying UFOs or ghosts, but claims concerning> them. Len.>So then Chemistry does not concern real atoms, but the claimed observancesof atoms ?? Where does reality t in ??Music does not concern real notes, but merely the claim that someone heardmusic ?I would like to know if you can do valid science uopn things like UFOs andghosts, things which cannot be proven to exist in the rst place.I am not confused sha1:NNadUaabT3N18nSX/QLbNIqnGe8 => You are confused as to what you are studying. The correct>> conclusion is that CLAIMED SIGHTINGS of UFOs correlate with CLAIMED>> SIGHTINGS of ghosts. You are not studying UFOs or ghosts, but>> claims concerning them. So then Chemistry does not concern real atoms, but the claimed observances> of atoms ?? Where does reality t in ??You are confused. Statistics concern WHAT YOU ACTUALLY MEASURED. Ifyou counted people who claimed to see a UFO, then thats what youvemeasured: people claiming to have seen a UFO. Now you know that thatmany people have made such a claim. You have no idea whether theyreally saw UFOs, or indeed whether UFOs exist at all. You didntmeasure that; you measured CLAIMS.Similarly, if a survey (in Berkeley!) determines that 81% of peoplesurveyed describe Bush as a weenie, you have learned something aboutthe opinions of people in Berkeley. You have not learned anythingabout whether Bush is indeed a weenie, nor that he has an 81%chance of being a weenie, nor anything else about Bush. You learnabout the measurement you ACTUALLY MADE.> I am not confused on this. Address the question.If you want to know whether extraterrestrial spacecraft exist, pollingearthlings is a useless procedure. If you _hypothesize_ that claimedsitings correlate with real sitings, then you might use thatinformation to devise a good experiment for proving that ETsexist. But the surveys yield absolutely no data on that question.Your question was, what is the aw in this reasoning. The answer isthat you measured one thing, and then drew a conclusion about anunrelated thing. If you dont fully realize that, then you AREconfused.Len. > You are confused as to what you are studying. The correct>> conclusion is that CLAIMED SIGHTINGS of UFOs correlate with CLAIMED>> SIGHTINGS of ghosts. You are not studying UFOs or ghosts, but>> claims concerning them. So then Chemistry does not concern real atoms, but the claimedobservances> of atoms ?? Where does reality t in ?? You are confused. Statistics concern WHAT YOU ACTUALLY MEASURED. If> you counted people who claimed to see a UFO, then thats what youve> measured: people claiming to have seen a UFO. Now you know that that> many people have made such a claim. You have no idea whether they> really saw UFOs, or indeed whether UFOs exist at all. You didnt> measure that; you measured CLAIMS.I am not confused on this. I fully understand what you are saying, and Iagree. You cannot measure one thing and claim statistical relsults forsomething unrelated.You seem to be confused about something though - the fact that nothingregarding UFOs can be measured, other than the prevalence of hallucinationsof the various observers. You cannot assemble a collection of UFOs orghosts, or vampires, or any other mythical nonsense. Such sets cannot beassembled. If you want to measure marbles you can do so. But you cant takethe average height, weight, etc of vampires because they do not exist.You can spend the next 40 years doing statistical analysis on vampires,but none of it is valid science because your population is non-existent.I am talking about real science - not abstractions. I am talking about theset of rael world vampires, and not the world of hypotheticalabstractions.> Similarly, if a survey (in Berkeley!) determines that 81% of people> surveyed describe Bush as a weenie, you have learned something about> the opinions of people in Berkeley. You have not learned anything> about whether Bush is indeed a weenie, nor that he has an 81%> chance of being a weenie, nor anything else about Bush. You learn> about the measurement you ACTUALLY MADE.Or - did you learn something about the response to a single question on aparticular day in history at a particular place ?You learn nothing about opinions of people at berkely from this - all youlearn is the response you will recieve to a particular question, on aparticular day in historty, at a specic place.> I am not confused on this. Address the question. If you want to know whether extraterrestrial spacecraft exist, polling> earthlings is a useless procedure. If you _hypothesize_ that claimed> sitings correlate with real sitings, then you might use that> information to devise a good experiment for proving that ETs> exist. But the surveys yield absolutely no data on that question.I am talking not about sightings. I am talking about actual alienspacecraft from other worlds - the real thing, the actual spacecraft. Myquestion is as follows -If you do not posses the actual spacecraft, is it possible to performgenuine scientic analysis of the spacecraft ?I claim that the answer is an absolute _no_It sounds stupid, but this is the verication I seek.> Your question was, what is the aw in this reasoning. The answer is> that you measured one thing, and then drew a conclusion about an> unrelated thing. If you dont fully realize that, then you ARE> confused.Well Len, I appreciate your input. But you are only %50 right. The correctanswer has to do with populations. I do not even have a valid population towork with, and so EVERYTHING is moot - no science is possible whatsoever. Doyou see what Im talking about ? I hope so, because it aint that difcult.Is it possible to go out and capture a Leprachaun ? Would it be rational toy over to Scotland in hopes of riding the Loch Ness Monster up and downthe loch ?? Is it possible to perform science upon objects which cannot beDEMONSTRATED as factually existing in sha1:n4MK+qiHS0rDu3B+orKstk2JycI == I am not confused on this. I fully understand what you are saying, and I> agree. You cannot measure one thing and claim statistical relsults for> something unrelated.So far, so good.> You seem to be confused about something though - the fact that> nothing regarding UFOs can be measured, other than the prevalence> of hallucinations of the various observers...I already said that. With one exception: you cant conclude thatsightings are in fact hallucinations, any more than you canconclude that theyre real. You can only claim that a sighting wasreported.> You can spend the next 40 years doing statistical analysis on> vampires...You cannot. You can only do statistical analysis on claims concerningvampires.>> Similarly, if a survey (in Berkeley!) determines that 81% of people>> surveyed describe Bush as a weenie, you have learned something about>> the opinions of people in Berkeley. You have not learned anything>> about...Bush... Or - did you learn something about the response to a single> question on a particular day in history at a particular place ?Even better.> If you do not posses the actual spacecraft, is it possible to perform> genuine scientic analysis of the spacecraft ?If youll pardon my saying so, its a frivolous question. AND it hasNOTHING to do with your hypothetical survey concerning UFO sightings.> I claim that the answer is an absolute _no_It is.> It sounds stupid...It is.> Well Len, I appreciate your input. But you are only %50 right. The> correct answer has to do with populations. I do not even have a> valid population to work with...If you did a valid survey, then you DID have a validpopulation. Namely, the population of people who may or may not havesighted a UFO. And you can do all sorts of scientic studiesconcerning that population.That population, however, has nothing to do with UFOs. You do not havea population of aliens.But you ARE confused: otherwise you would not keep repudiating your ownhypothetical survey on the grounds that it is not some other survey.Len. You can spend the next 40 years doing statistical analysis on> vampires... You cannot. You can only do statistical analysis on claims concerning> vampires.You could, but it would all be garbage. This is my point.>> Similarly, if a survey (in Berkeley!) determines that 81% of people>> surveyed describe Bush as a weenie, you have learned something about>> the opinions of people in Berkeley. You have not learned anything>> about...Bush... Or - did you learn something about the response to a single> question on a particular day in history at a particular place ? Even better. If you do not posses the actual spacecraft, is it possible to perform> genuine scientic analysis of the spacecraft ? If youll pardon my saying so, its a frivolous question. AND it has> NOTHING to do with your hypothetical survey concerning UFO sightings. I claim that the answer is an absolute _no_ It is. It sounds stupid... It is. Well Len, I appreciate your input. But you are only %50 right. The> correct answer has to do with populations. I do not even have a> valid population to work with... If you did a valid survey, then you DID have a valid> population. Namely, the population of people who may or may not have> sighted a UFO. And you can do all sorts of scientic studies> concerning that population. That population, however, has nothing to do with UFOs. You do not have> a population of aliens. But you ARE confused: otherwise you would not keep repudiating your own> hypothetical survey on the grounds that it is not some other survey. Len.>OK then - I am confused. No problem. I do understand what you are saying -that the exampel in the original post was basically a mathamaticalknow what I mean.The point, being, that you cannot measure the velocity of Superman inight, because you cannot collect real data on mythical or nonexistentobjects/people.Similarly, for the folks in alt.psychology, you cannot measure love, hate,etc. You cannot do statistics on things which cannot be measured or observedproperly. Any science which claims to do this, sha1:FvC/+AaGDK5yYiLf9S44RFi/zrc => You can spend the next 40 years doing statistical analysis on vampires...>> You cannot. You can only do statistical analysis on claims>> concerning vampires. You could, but it would all be garbage. This is my point.You cannot. If you are discussing statistics, then it is not ofparticular interest how some idiot misuses them to provenon-sequiturs.>> But you ARE confused: otherwise you would not keep repudiating your>> own hypothetical survey on the grounds that it is not some other>> survey. OK then - I am confused. No problem. I do understand what you are> saying - that the exampel in the original post was basically a> mathamatical non-sequiter...Correct.> The point, being, that you cannot measure the velocity of Superman> in ight, because you cannot collect real data on mythical or> nonexistent objects/people.The only problem is that its confusing when you describe oneexperiment (a survey of Superman sightings) and discuss another(Supermans airspeed). What you need to do is to get absolutely clearwhat your question is, and then design an experiment that addressesTHAT question.> Similarly, for the folks in alt.psychology, you cannot measure love,> hate, etc...Cant comment: vast amounts of research in the soft sciences isdeeply awed, for lots of reasons.> You cannot do statistics on things which cannot be measured or> observed properly.Love can be dened as an immeasurable, intangible thing, or it canbe dened to be consonant with the perception thereof--i.e., that theassertion I love X, if honest, is true.> Any science which claims to do this, thus far, is bogus academic> fraud.Hmm. If the whole point of your question is to advance some crankishclaim that the whole eld of psychology is invalid, then Im sorry Ireplied.Len. = You can spend the next 40 years doing statistical analysis on vampires...>> You cannot. You can only do statistical analysis on claims>> concerning vampires. You could, but it would all be garbage. This is my point. You cannot. If you are discussing statistics, then it is not of> particular interest how some idiot misuses them to prove> non-sequiturs.Well, one could dene vampires as being x,y,z, or you could dene theset of all vampires V {V| a,b,c...etc}, and then you could do all kinds ofvalid mathamatics.What I am talking about is actually going out into the physical world as aphysicist or chemist would, rounding up a group of vampires and collectingdata on them.Now, I could be wrnog here, but last tiem I checked, there were no realvampires. The cardinality of the set of all vampires in our physical worldis assumed to be zero. I could do all kinds of statistics on people who Ithink are probably vampires, but if ther are not genuine vampires then myanalysis is just garbage.>> But you ARE confused: otherwise you would not keep repudiating your>> own hypothetical survey on the grounds that it is not some other>> survey. OK then - I am confused. No problem. I do understand what you are> saying - that the exampel in the original post was basically a> mathamatical non-sequiter... Correct. The point, being, that you cannot measure the velocity of Superman> in ight, because you cannot collect real data on mythical or> nonexistent objects/people. The only problem is that its confusing when you describe one> experiment (a survey of Superman sightings) and discuss another> (Supermans airspeed). What you need to do is to get absolutely clear> what your question is, and then design an experiment that addresses> THAT question.I apologize. Admitted, the original post was thrown together rather hastily.> Similarly, for the folks in alt.psychology, you cannot measure love,> hate, etc... Cant comment: vast amounts of research in the soft sciences is> deeply awed, for lots of reasons.Agreed. You need not take a position here, and I dont blame you forremaining neutral on what I am about to say - but MY position is thatpsychology is mostly garbage for the very reasons I am discussing here.Without any method of making physical measurements of human emotion or willor intent, either quantitative or qualitative, one simply cannot generateany solid science.> You cannot do statistics on things which cannot be measured or> observed properly. Love can be dened as an immeasurable, intangible thing, or it can> be dened to be consonant with the perception thereof--i.e., that the> assertion I love X, if honest, is true.Yes - it can be dened many ways. But can it be measured directly ?You have a couple approaches here. You can model it algebraicly, in whichcase you are treating a metaphysical entity as an abstraction. So, it startsgetting fairly strained already to say the least. You must somehow denelove using human speech language otherwise your variables are inaccurateor incomplete - something which may not be possible with a nite amount ofstatements. Even if you succed, and you would then be immediately famous,there is no way to verify that you have modelled love because love cannot bemeasured with instruments.Hell - we cannot even prove that love exists. I do not dispute that it does,but you can never tell when you are observign love or something else whichjust looks like love, and then how many kinds of love are there ?This is a nightmare - and all because such items are metaphysical in nature.> Any science which claims to do this, thus far, is bogus academic> fraud. Hmm. If the whole point of your question is to advance some crankish> claim that the whole eld of psychology is invalid, then Im sorry I> replied.That is exactly the point and Im sorry that you feel sorry, but it is notone bit crankish to discard rubbish.In fact - it is very crankish, but also very very true that psychology isfraud.> Len. In fact - it is very crankish, but also very very true that psychology is>fraud.>Perhaps. Cant really comment (the only book I have in my library, ThePsychology of Rigorous Humanism by Rychlak, makes about as much sense as, say,Bolzanos Paradoxes of the Innite). It is however quite clear to me thatscience doesnt give answers to all answerable questions. Think about it,mathematics *barely* qualies as a science, is it therefore fraud? Hardly. Amazingly enough, mathematics still manages to provide answers to questions ona fairly regular basis. Almost mystical isnt it?And now its time for me to see if I won this weeks lotto ($88kk +/-). rich In fact - it is very crankish, but also very very true that psychology is>fraud.> Perhaps. Cant really comment (the only book I have in my library, The> Psychology of Rigorous Humanism by Rychlak, makes about as much sense as,say,> Bolzanos Paradoxes of the Innite). It is however quite clear to methat> science doesnt give answers to all answerable questions. Think about it,> mathematics *barely* qualies as a science, is it therefore fraud?Hardly.> Amazingly enough, mathematics still manages to provide answers toquestions on> a fairly regular basis. Almost mystical isnt it? And now its time for me to see if I won this weeks lotto ($88kk +/-). rich>answer all questions, because then it would almost be providing the truth,which is seemingly impossible.Im not sure about math not qualifying as science, however. I think that itmay. What is the denition of a science ? Results must be veriable,falsiable, and reproducible. I think that math satises these threebetter than any physical science, and it does so with complete precision andan exactness which is unique to math. If you know something that I dontplease post. My claim that psychology is fraud is based on the fact that I do notbelieve that they can qualify or quantify the objects which they claim tostudy. As an extreme example, consider making a statement about depressedpeople. One cannot prove who belongs and who does not belong in the dataset, and therefore the data set could be completely messed up and nobodywould ever know. In other words, depression cannot be qualied. There is noinstrument to test for depression. Also, depression cannot be quantied. There is no way to know howsevere it is. There is no meter to measure its strength. What can be known about depression if you cannot qualify your dataset,and you cannot quantify your data ?? I will tell you how much can be known.Nothing. Nothing can be known. Yet mountains of statistics a churned out,and it seems that I am the only one who is bold enough to admit that I amcurious to say the _very_least. =Im not sure about math not qualifying as science, however. I think that it>may. What is the denition of a science ? Results must be veriable,>falsiable, and reproducible. I think that math satises these three>better than any physical science, and it does so with complete precision and>an exactness which is unique to math. If you know something that I dont>please post.>Where are the experiments? Is the scientic method taught in math classes? Ever try to verify a number is not computable experimentally? Why are therecolleges of science *and* math? I could go on, but Im too depressed over notwinning the lottery. And yes, my depression is quantiable...to the tune of$88kk :(rich Im not sure about math not qualifying as science, however. I think thatit>may. What is the denition of a science ? Results must be veriable,>falsiable, and reproducible. I think that math satises these three>better than any physical science, and it does so with complete precisionand>an exactness which is unique to math. If you know something that I dont>please post.> Where are the experiments? Is the scientic method taught in mathclasses?> Ever try to verify a number is not computable experimentally? Why arethere> colleges of science *and* math? I could go on, but Im too depressed overnot> winning the lottery. And yes, my depression is quantiable...to the tuneof> $88kk :(I see that you ve qualied it - and quantied it !! Perhaps your lossesare amenable to real scientic explorations.But returning to math, I think that the experiments are replaced by theactual practice of performing algebra or even conceptualizing. Proofs allowthsee conceptualiztions to be repeated by others for independentverication.The use of algebra in place of experiments. I guess Im reminded that thereis a debate as to whether mathematics is a discovery of naturally occuringrelationships, or merely some type of manmade contraption. I do not know theanswer. But I do know that physical scientists are engaged in both discovery_and_ invention.Some genuine experimentation is now possible using computers as well.I think that the division between math and science formed as a result of twodistinct needs. On the one hand you need engineers who are practical andable to make things work in the real world such as industry. On the otherhand, you need the eggheads, the experts, the idiot savants who study mathlike hermits seldom shaving and working away as diligently as rust trying tosolve the difcult problems. These are two fundamentally differentcreatures.But then you have modelling - which is more like a ne art.I honestly dont know either. = What I am talking about is actually going out into the physical> world as a physicist or chemist would, rounding up a group of> vampires and collecting data on them.Then stop talking about experiments in which you collect data onaverage rainfall, and then draw conclusions about vampires.> Now, I could be wrnog here, but last tiem I checked, there were no real> vampires.That is the standard assumption, yes. It is possible, however, forscientists to treat the question as open in order to prove or disprovethe hypothesis.> The cardinality of the set of all vampires in our physical world> is assumed to be zero.If you do assume that, then any arguments you make about theirnonexistence are likely to be circular.> I could do all kinds of statistics on people who I think are> probably vampires, but if ther are not genuine vampires then my> analysis is just garbage.It might be perfectly valid research on Goths, or self-proclaimedvampires, or People that Toilet considers weird, depending how yourcohort is selected.Over and over, you describe a perfectly valid experiment concerning X,and then argue that it isnt valid because it isnt an experimentconcerning Y. This suggests that you havent got a rm grip on thescientic method.> ...MY position is that psychology is mostly garbage for the very> reasons I am discussing here.It may or may not be, but youre having trouble making the point,because you seem to have trouble understanding the scientic methodin general.> Without any method of making physical measurements of human emotion> or will or intent, either quantitative or qualitative, one simply> cannot generate any solid science.There are lots of interesting ways. People are generally honest enoughthat their claims to like one thing, and dislike another, willcorrelate pretty well with the truth. Involuntary responses such aspupil dilation and skin temperature have also been used to good effect.>> Love can be dened as an immeasurable, intangible thing, or it>> can be dened to be consonant with the perception thereof... Yes - it can be dened many ways. But can it be measured directly ?Thats a good question for a philosophy class; you could get an A onan essay about it. In practice, the answer is often well enough.> Hell - we cannot even prove that love exists...Or that you exist. You arent talking science, but philosophy.> That is exactly the point and Im sorry that you feel sorry, but it> is not one bit crankish to discard rubbish.Until you understand how experiments work, and what they do or donttell you, you will be unable to distinguish the wheat from the chaff.> In fact - it is very crankish, but also very very true that psychology is> fraud.I have no wish to help you grind your axe. Im off this thread.Len. =garbage snipped> Over and over, you describe a perfectly valid experiment concerning X,> and then argue that it isnt valid because it isnt an experiment> concerning Y. This suggests that you havent got a rm grip on the> scientic method.It is psychology which is ignoring the scientic method, to the detrimentof mankind, making a mockery of academia through its sanctioned fraud.What I said was very clear. Pay attention and then respond after thinkingcarefully.Show me how this discipline which you seem to defend is actually observingthe scientic method. It does not. It is fraud.> ...MY position is that psychology is mostly garbage for the very> reasons I am discussing here. It may or may not be, but youre having trouble making the point,> because you seem to have trouble understanding the scientic method> in general.Strawman -you lose.> Without any method of making physical measurements of human emotion> or will or intent, either quantitative or qualitative, one simply> cannot generate any solid science. There are lots of interesting ways. People are generally honest enough> that their claims to like one thing, and dislike another, will> correlate pretty well with the truth. Involuntary responses such as> pupil dilation and skin temperature have also been used to good effect.People are frequently WRONG. You have no means to prove this - you arepromoting quackery and fraud.You do not understand that science has requirements which must be satised.You have deomstrated this in writing.>> Love can be dened as an immeasurable, intangible thing, or it>> can be dened to be consonant with the perception thereof... Yes - it can be dened many ways. But can it be measured directly ? Thats a good question for a philosophy class; you could get an A on> an essay about it. In practice, the answer is often well enough. Hell - we cannot even prove that love exists... Or that you exist. You arent talking science, but philosophy.And you are not a scientist, but a sociopolitical hack.> That is exactly the point and Im sorry that you feel sorry, but it> is not one bit crankish to discard rubbish. Until you understand how experiments work, and what they do or dont> tell you, you will be unable to distinguish the wheat from the chaff.You need to learn basic 8th grade material. Veriability, falsiability,and reproducibility. If you do not have these, then you do not have science.believe just because people say that it is true ? You have learned nothing.> In fact - it is very crankish, but also very very true that psychologyis> fraud. I have no wish to help you grind your axe. Im off this thread.Good, then run from truth.> Len.> I have determined that %77 of all ghosts are spotted within a 5 mile> radius of UFO sightings, and that %82 of all UFO sightings are> accompanied by a general increase in the intensity and overall> magnitude of ghost related hauntings. Therefore, I conclude, via statistics, that ghosts and UFOs are somehow> related, and that ghosts are in all probability using UFOs for> transportation purposes. Will someone in the sci.math or sci.math.stat please stand up and> tell me why this is awed, and no I am not kidding. I need an> independent opinion. You are confused as to what you are studying. The correct conclusion> is that CLAIMED SIGHTINGS of UFOs correlate with CLAIMED SIGHTINGS of> ghosts. You are not studying UFOs or ghosts, but claims concerning> them. Len.>one of the many aws.However, it is not quite the glaring aw that Im looking for, butcertainly valid.Im looking for a much more obvious aw, if anyone has an idea, please -please feel free to respond. am facing with this difcult problem. Please help me!In this problem, I need to construct some matrices which satisfy thefollowing matrix equation:(( A * A )V1 + ( B * B) V2) V = (D * D)where * denotes Kronecker product, A, B, V1, V2, V are unknown matricesthat needs solving; they are all square. Some structure needs to be imposed:I have certain pattern for A and B; and V1, V2, and V are required to bediagonal... Matrix D is given...The task is tofind the best approximation of the above-mentioned A, B, V1,V2 and V... I have been thinking about this for long time... can anybodygive me some hints?Is it possible to have closed form analytical solution? Have anybodyresearched on this problem before?Is it possible and how to design iterative algorithm to let computer searchfor the answer?-Walala problem. Please help me!In this problem, I need to construct some matrices which satisfy thefollowing matrix equation:(( A * A )V1 + ( B * B) V2) V = (D * D)where * denotes Kronecker product, A, B, V1, V2, V are unknown matricesthat needs solving; they are all square. Some structure needs to be imposed:I have certain pattern for A and B; and V1, V2, and V are required to bediagonal... Matrix D is given...The task is tofind the best approximation of the above-mentioned A, B, V1,V2 and V... I have been thinking about this for long time... can anybodygive me some hints?I guess it is difcult tofind closed form analytical solution... How todesign iterative algorithm to let computer search for the answer? It isreally hard... please help me!-Walala facing with this difcult problem. Please help me!In this problem, I need to construct some matrices which satisfy the>following matrix equation:(( A * A )V1 + ( B * B) V2) V = (D * D)where * denotes Kronecker product, A, B, V1, V2, V are unknown matrices>that needs solving; they are all square. Some structure needs to be imposed:>I have certain pattern for A and B; and V1, V2, and V are required to be>diagonal... Matrix D is given...The task is tofind the best approximation of the above-mentioned A, B, V1,>V2 and V... I have been thinking about this for long time... can anybody>give me some hints?I guess it is difcult tofind closed form analytical solution..How diicult is it - it seems to me that the problem has an awful lotof structure.>. How to>design iterative algorithm to let computer search for the answer? It is>really hard... please help me!You are trying to solve the nonlinear system of equations(( A * A )V1 + ( B * B) V2) V - (D * D) = 0If the problem is not too large use Newtons method. If the problemis too big for that look for a canned program that will solvenonlinear systems without needing to generate and then solve thejacobian. >-Walala =I am reading a book on memory techniques and it has the following passage:... some scholars insist that Leibniz invented calculus while searching fora memory system that would aid in memorizing numbers.Several questions.1. Is there any proof of this?2. Why would this be deemed an important pursuit (what is the big deal withmemorizing numbers) for Leibniz?3. Is there anything Leibniz produced if this pursuit is true (writings orbooks on the matter)?4. How did (I believe a Japanese person) memorize something on the O(42000)digits of the pi expansion? What technique is used to memorize such longsequences of numbers? IIRC correctly, Euler knew the decimal expansion ofe to at least a hundred digits or more. Same question, why and how?memorization is an important topic in any learning endeavor.Flip ......... IIRC correctly, Euler knew the decimal expansion of> e to at least a hundred digits or more. Same question, why and how?> I have heard that Euler invented (or discovered) e. I can see why if someone had made such an important discovery, that they would be highly motivated to remember it.I discovered the far less important number 3,386,001,688 - at least I think that I was the rst tofind it - I was denitely motivated to remember it, at least for a day or so. (It is the number of ways of placing the twelve pentominoes and ve tetrominoes into an 8x10 rectangle.)Well, from the sublime to the ridiculous.....Stephen Message-id: > ......... IIRC correctly, Euler knew the decimal expansion of>> e to at least a hundred digits or more. Same question, why and how?>I have heard that Euler invented (or discovered) e. I can see why if >someone had made such an important discovery, that they would be highly >motivated to remember it.I discovered the far less important number 3,386,001,688 - at least I think>that >I was the rst tofind it - I was denitely motivated to remember it, at>least >for a day or so. (It is the number of ways of placing the twelve pentominoesand ve tetrominoes into an 8x10 rectangle.)Well, from the sublime to the ridiculous.....I discovered a number also. Mine has over 53000 digits and no, I have made noattemptto memorize them. Instead, I memorized the formula that generates itn = 2**(6*(4*9**4 + (9**4 - 1)/2 + 1) - 1) - 1This is the rst Sixth Generation Type 21211 Mersenne Hailstone.Stephen--MensanatorAce of Clubs =It is usually best not to change the subject line unless the topic ofthe post has changed substantially from the original. [.snip.]> This is not my question, however. It is:>> (Idea- since {1,-1} is a nontrivial group, ...),What does -1 mean in the context of an arbitrary group? > > Of course, you are correct here. I suspect one could say> the following: Given an arbitrary group (G, *), let (R, *, +)> be any ring such that G is a subgroup with respect to * and > in a way that every additive inverse of G is in G,There are too many such rings. For any ring R, the natural choice isR[G], the group ring over R, which consists of all polynomials ofthe formsum_{g in G} a_g*gwhere a_g is in R, only nitely many nonzero, with multiplicationgiven by multiplying monomials as(a_g*g)(a_h*h) = (a_g*a_h)(gh) ^ ^ | |____ multiplication in G multiplication in R.Then G embedds as the collection of all elements of the form 1*g, 1the multiplicative identity in R; its additive inverse is (-1)*g,where -1 is the additive inverse of 1 in R. If you choose R to beany ring of characteristic 2, then -1 = 1 in R, so the additiveinverse of the element 1*g is again 1*g, which is in the image of thecanonical embedding of G. In fact, this is the only situation in whichthis will happen in the group ring. I guess there could be other ringsin which this can be done, quotients of group rings overcharacteristic different from 2.> then -1(R) is the additive inverse of 1 with respect to + What does -1(R) mean? R is a ring. Are you multiplying every elementof R by -1?Or do you mean, the -1 from R? There is no reason to assume this isdifferent from 1, either, as noted above.> and is in G. If no such ring exists then G does not have > a -1.And what makes you think that (1) -1 will be different from 1, the identity of G? (2) In any two such rings, -1 will be the same element of G?Unless both questions have an afrmative answer (and clearly, (1)certainly does not), it still makes no sense to talk about -1 in anarbitrary group G.> My Guess is as Good as Yours Theorem 1.1:> the element -1 designated as above is independent> of the encompassing ring (R, *, +). In a group ring over a ring of characteristic 2, it will be equal to1. In other rings, it need not be.>And what makes you think that in your group, even if -1 makes sense,>-1 is not equal to 1? Using the technique above, it would follow that 1 is no longer > a unit, am I right?I do not see how that follows. In (F_2)[G], 1, by which you presumablymean 1*e, e the identity of G, is a unit.Arturo Magidin, sans .sig To all: please excuse my not being good at following what others>have done. The problem was not your failure to follow; the problem was your> acting as though you had followed it and claiming an imaginary error> in the material that you did not follow. Admitting ignorance and> asking for clarication would have yielded a different thread. Because of my different perspective I thought I saw an error inaccepted theory where in fact there was none. I have tried toapologise for sticking out on it for as long as I did and hope that itmay now be forgotten.>But one may think that>branches are worth studying for there own sake, and then in context>just think of Riemann surfaces as a byproduct. > > Certainly, although I dont see the motivation for it. At rst> reading your analysis in those terms seems correct. Motivation is subjective so perhaps we could agree to differ on thispoint. Happy Xmas to all Sci.* NG!> > And to you Abhi, forget the device and have a good time.> > George___________________________________________Mere Ghar Ka Seedha Sa Itna Pataa HaiYe Ghar Jo Hai Chaaron Taraf Se Khula HaiNa Dastak Zaruri, Na Aavaz DenaMere Ghar Ka Darvaaza Koi Nahin HaiHain Deevaren Gum Aur Chhat Bhi Nahin HaiBadhi Dhoop Hai DostKadhi Dhoop Hai DostTere Aanchal Ka Saaya Churake Jeena Hai Jeena Jeena Zindagi, ZindagiO Zindagi Mere Ghar AanaAana Zindagi Zindagi Mere Ghar Aana_______________________________________________I am still alive and back in comfort of my own room from where allthis saga began in March 2000.I got new beautiful computer, listening beautiful songs right now incalm night.Happy new year to all of you!I am still in Action...-Abhi. > Happy Xmas to all Sci.* NG! And to you Abhi, forget the device and have a good time. George ___________________________________________ Mere Ghar Ka Seedha Sa Itna Pataa Hai> Ye Ghar Jo Hai Chaaron Taraf Se Khula Hai> Na Dastak Zaruri, Na Aavaz Dena> Mere Ghar Ka Darvaaza Koi Nahin Hai> Hain Deevaren Gum Aur Chhat Bhi Nahin Hai> Badhi Dhoop Hai Dost> Kadhi Dhoop Hai Dost> Tere Aanchal Ka Saaya Churake Jeena Hai Jeena> Jeena Zindagi, Zindagi> O Zindagi Mere Ghar Aana> Aana Zindagi Zindagi Mere Ghar Aana> _______________________________________________ I am still alive and back in comfort of my own room from where all> this saga began in March 2000. I got new beautiful computer, listening beautiful songs right now in> calm night. Happy new year to all of you! I am still in Action... -Abhi.Dont you realize that They are watching you throughthe new computer.... Computing machines.> > If an a-machine prints two kinds of symbols, of which the rst kind> > (called gures) consists entirely of 0 and 1 (the others being> > called symbols of the second kind), then the machine will be called> > a computing machine. If the machine is supplied with a blank tape> > and set in motion, starting from the correct initial m-conguration, Please dene m-conguration, as dened in Turings paper. I think he means what is now called the state transition table.> The TMs instructions. According to Turings paper, to which you have kindly provided alink, an m-conguration is what we today would call a state.http://www.abelard.org/turpap2/tp2-ie.asp#section-1Its not the whole transition table; its merely one of the stateslisted in that table (which may or may not be said to contain therest of the table; thats a philosophical point thats not relevanthere). For example, State 1 is an m-conguration. State 2is a different m-conguration. The machine, Turing says, will start in the correct initialm-conguration, which is just his way of saying that it has adened starting state.> Okay. Here Turing is apparently assuming that the sequence printed> by the machine will have a beginning, though not necessarily an end.> Its not clear how he denes the beginning of the sequence, though --> is it left-to-right order? or chronological? Left-to-right has the> advantage of intuitiveness, but chronological makes more sense> mathematically to me. Please clarify this point: briey, what does> Turing mean by the word prefacing? Turing assumes that all TMs start in a dened initial state at the> beginning (leftmost) position of a blank tape. Okay; this makes the most sense, so Ill accept it. Unfortunatelyfor us, Turing simply does not say in his paper what shape the tapeis supposed to be. In other words, he denes the symbols on thetape, S(r), in terms of their positions r; but he never denes therange of r. Is r an integer, a positive integer, an integer in therange [0, 1024), or something else entirely?*not* what Id originally been thinking -- I had been assuming thatr was an integer (positive or negative), and thus that the tape wastwo-way innite instead of only one-way innite. If you dontsee the difference, or dont understand what those phrases are meant> I think Turing assumes the output tape will be read from left to right.> Later in the paper, Turing adopts the convention of only writing> symbols of the rst kind on every other square.> the 0s and 1s. He states that these other symbols are removed> at some point, but isnt very specic about when or how this happens. I think you are correct. Symbols of the rst kind may not beoverwritten, although symbols of the second kind may be overwritten.The tape is read from left to right, and only symbols of the rstkind matter as far as the computed sequence is concerned.> Prefacing means putting a decimal point in front of a binary string.> Turing is trying to show that a TM can generate any real number. Yes. Now that I realize that r is constrained to be positive,this makes sense -- there is always a left side of the tape atwhich we can insert a decimal point (at r=0, so to speak).> > Circular and circle-free machines.> > of symbols of the rst kind it will be called circular. Otherwise> > it is said to be circle-free. All right. This is fairly bizarre terminology, IMHO -- do you have> any idea why Turing chose these particular words to describe the two> kinds of machines? Perhaps a quote from section 8 would be in order. I have no idea why Turing denes computable numbers this way. I was actually referring to the terms circular and circle-freeto describe machines that we today would see were exactly isomorphicto [but not identical to] the terms halting and non-halting. Whatdoes the idea of circle have to do with the nitude of symbolsprinted by a machine? [Rhetorical -- unless you really have someetymology here, dont bother answering that. Just a claricationof what I meant.]> > > Instructions for TM2:> > > > 1) Scan right until a 0 is found> > > 2) Scan right until a second 0 is found> > > 3) Backup and write a 1 on the previous 0> > > Repeat > Using Turings denition, TM2 produces a computable sequence I doubt it. This depends heavily on the denition of the word> prefacing in Turings paper. Im sorry, I misread your machine. I read right and thoughtleft. Obviously, TM2 is exactly equivalent in its output to TM1(assuming that the tape starts out with all 0s on it, or doing asyou suggested and replacing the word 0 by the word blank).> > that represents the largest rational number less than 1. Blatantly false. No such number exists, computable or otherwise.> Thats like saying that your machine computes the number of digits> in pi, or a recipe for granite cheesecake. This sequence may not represent a real number, but it is computable. All computable sequences, by denition, represent real numbers.Any sequence of zeroes and ones, prexed by a point, is the digitalrepresentation of *some* real number. Unless the antecedent of this sequence is granite cheesecake,in which case youre half right; granite cheesecake is not a realnumber, but neither is it computable by Turings method.> > .111...1110 (base 2) This is not correct notation. It reminds me very strongly of> Phils ramblings, and I really do suggest you take a look at> Google Groups for sci.math, and search on rational numbers> countable, largest integer, and terms of that nature. I dont know who Phil is, but I have started several> threads about the largest natural number.Google Groups phil sci.math numbers> I dont know why youfind the idea so bizarre.> The idea that there is a nite number of natural numbers> is certainly not as strange as the idea that there are> more real numbers than natural numbers. Perhaps not -- but its certainly not as correct!> Several people have suggested that this proof says> there is a nite number of natural numbers.> This is incorrect. Right.> This proof shows that no set> can contain every natural number. Wrong. Consider the set usually written blackboard-bold /N/,the set of natural numbers. Its the set {0,1,2,3,...}. Itcontains all natural numbers. It can be constructed inductivelyas the set S such that 0eS and xeS->(x+1)eS, where e representsthe is-an-element-of relation.> This is not the same as saying there is a largest natnum. Just the opposite.> A set cant contain every natnum precisely because> there in no largest natmun. Luckily for the universe, there is no logical requirement thatevery set must contain a largest element. Consider the set ofeven numbers, or the set of real numbers less than 1, or theset of Greek playwrights.> > This is essentially the same reason Turing gives why> > the diagonal argument doesnt work with computable numbers.> > The problem can be converted into determining whether> > every TM is circular or not.> > Turing proves this is impossible While it is certainly impossible to determine whether Turing> Machine X is circular, for some value of X, it doesnt necessarily> follow that the computable numbers are uncountable. For that,> youd need to actually give a reference to Turings proof, so> that we could look at it and see whether it proves what you think> it does. It does not. Im embarrassed that I did not see the reversalearlier. Cantors diagonal argument, applied to the real numbers,proves that R is uncountable. Turing showed that the diagonalargument could *not* be applied to the computable numbers, whichmeans that he did *not* prove that the set of computable numberswas uncountable.> > TM2 is not an arbitrary TM. It is easily specied.> > If we can not determine if TM2 is circle free,> > how can we say that any TM is circle free? TM2 is circle-free. It never stops printing 1s, which aresymbols of the rst kind. Thus by denition it is circle-free. No it doesnt.> At least, no one can prove that it does. I can. Inductively; in the same way that I can show that ifI give an idiot a card reading Turn this card over.on both sides, and the idiot obeys the orders on the card, hewill never stop turning the card. In the same way, the ordersyou gave to TM1 tell it to keep printing 1 forever; thus, itwill never stop printing 1s.> It is simple to show that the number of 1s> written by TM1 is some multiple of the number> of 1s written by TM2.> Inductively.>A Turing machine can certainly> compute the following irrational number, though I have not bothered> to write out its state transitions: .1011011101111011111011111101111111011111111011111111101111111 1110... This is the same sequence I use in Cardinality of Computable Numbers.> Turing gives a similar string as an example of the output of a TM.> He provides a state table to produce the string 001011011101111... If you let TM2 read this tape it will produce a sequence, of 1s> followed by a 0, that is longer than any such sequence on the initial tape. Incorrect. Besides, even if you did let TM2 start with this tape,that wouldnt produce a computable sequence -- computable sequencesare made starting with a blank tape, according to Turings paper.> That number, which is approximately 0.71673, is computable, but> certainly not rational! Also computable: pi and e, among many> others. These numbers are computable only if you can show there is> a circle free TM that computes the relevant innite sequence.> I doubt any TM can be shown to be circle free as Turing denes it. You just said that Turing had given a state table for a TM thatcomputed 0.71673...! Obviously that number is computable by a TM,then -- its computable by the TM that Turing just nished dening! Read the responses to Phils ramblings before proceeding alongthis line of inquiry -- youre getting in way over your head invery shallow water.-Arthur = No it doesnt.> At least, no one can prove that it does. I can. Inductively; in the same way that I can show that if> I give an idiot a card reading Turn this card over. on both sides, and the idiot obeys the orders on the card, he> will never stop turning the card. In the same way, the orders> you gave to TM1 tell it to keep printing 1 forever; thus, it> will never stop printing 1s. It is simple to show that the number of 1s> written by TM1 is some multiple of the number> of 1s written by TM2.> Inductively.Turing doesnt say that computable numbers require induction.It is easy to prove that the output of TM2 is nite.TM2s tape will always have a string of 1s followed by a blank.The blank must be at a nite position.It is impossible for TM2 to write an innite string of 1s.Russell- 2 many 2 count [re: Russell Easterly]> Its funny that since I started reading these newsgroups a year or two> ago, Ive encountered at least half a dozen people arguing exactly the> same point of view as you, but in different contexts. Now were in the> context of Turing Machines. Thats very humorous to me. I didnt know> people with your beliefs existed, and now Ifind that there are at least> several of you.> > I can easily understand how some people dont get innity. I> myself still dont quite get ordinal numbers, although Ive got> the cardinals down pretty well now. :)> What I dont understand is how some people who dont get innity> seem to compulsively post *wrong* statements to the Internet, rather> than trying to understand *right* ones. And how a guy like Russell> can seem to have such a reasonable grasp of what a Turing machine> is, without having even a basic conception of the properties of the> integer numbers!> > Have you heard of this guy Phil who used to post absurd> things like the statement that all natural numbers have nitely> many digits? Its quite fascinating. I could write a book about it.> > I remember Phil. But I must point out that you forgot to complete> that thought: All natural numbers *do* have nitely many digits!Yes, sorry! Now Im posting absurd statements. Writing too quickly.I did mean to complete my thought.> But Phil made a leap from that true statement to the false statement> that *the number of* natural numbers was nite -- and stuck to it --> and thats what was absurd.> > -Arthur =By refuting any claim to the contrary.If you propose some nite number of 1s which you claim itnite number that you name _rst_. Thats the crucialpoint you persist in missing: it is impossible to uphold thenatural number is nameable, you are _required_ to _name_ thenumber you claim has the property that it denes the maximumnumber of 1s written; otherwise your claim is a meaninglessnoise. But as soon as you do so, I can immediately refute thatclaim by examining in detail the behavior of TM2 after it hasjust written the number of 1s you claim is the maximum, andmore 1, thus proving false your claim that your nite numberdenes the maximum number of 1s written. Since this can bedone for _any_ nite number, there is _no_ nite number thatdenes the number of 1s written by TM2, refuting the claimthat there is such a number.And when you write the output of TM2 as 1111...111(0)*, you arewrting nonsense, because there is _no denable place_ in theoutput of TM2 where that transition from 1s to 0s occurs.xanthian.-- By refuting any claim to the contrary. If you propose some nite number of 1s which you claim it> nite number that you name _rst_.This is pretty much my argument.I can alwaysfind a nite number bigger than all thenite numbers in some set.The output tape will always start with a string of 1sfollowed by a blank (or a 0).The blank must be in a nite position.Russell- 2 many 2 count =No, the exact opposite is obvious, just not to you.> The output tape will always start with a string of 1s> followed by a blank (or a 0).by which you claim I canfind that 0, and I can demonstrateyou cannot demonstrate that it is on the tape at any nitelocation, then you cannot demonstrate that it is on the tape_at all_, and this is the place where your intuition is failing,and real mathematical logic must be used, instead.To look at your problem another way, the word you used, always,is either a meaningless noise, or else you need to dene it tomake it not one. In the process of creating that denition, youwillfind you have destroyed your current intuition about thebehavior of TM2.> The blank must be in a nite position.No, it mustnt for the reasons I just explained. You aredoing something _wrong_. Rather than merely continuing tomake _the *same* set of incorrect claims over and over_, stopto _think through_ the objections you are receiving.You have given all the needed evidence that you have theintelligence to understand them, you just need to stop yourdependence on your failing intuition about innite processes,and do the hard work of understanding what you have been told,needed to overcome the errors into which your intuitionperpetually leads you.xanthian.-- This is pretty much my argument.> I can alwaysfind a nite number bigger than all the> nite numbers in some set.> This should be : I can alwaysfind some number bigger than all the nite numbers in some nite set-- PentoDe wereld was soep, en het denken meestal een vork,tot smakelijk eten leidde dat zelden. - H. Mulisch CLAP C:LAP Im not not an asshole, you are a fertilizerdispensing orice. =On 2 would you want to be in a contest where the objective is to provethat youre an asshole?--- say.By the way, get outta alt.atheism. Nobody here believes *anybody ispsychic so youre wasting bandwidth.-- Mark K. Bilbo - a.a. #1423EAC Department of Linguistic Subversion CLAP CLAP to you says Lord> > judging by the names of the 2 replies.> > CLAP CLAP> Clave and Clayton> > broadcaster.> > But OK, starting soon, I dont want you slandering me though> as part of your posts, what subject matter?> > And afterwards we collate the replies to measure my claim.> HercOh please do me a favour:1. Get a digital camera2. Make a picture of yourself in your favorite pose3. Load the picture on to your computer4. Reduce the picture to promise to publish your picture in my galery-- Wieland the Smith, AA#2040, EAC: herder of the trolls Dene the function f from (-inf,0] U [1,inf) to (-inf, inf) as follows:> > f(x)=x for x<=0> > f(x)=x-1 for x>=1> > Clearly this function is continuous over each of the two disjoint> intervals which make up its domain.> > But does it make sense to call the function continuous? (Its the gap in> the domain that bothers me.)> > > LIf you examine the endpoints of the half open intervals, youll see thatlim_{x->0-} f(x) = f(0), and lim_{x->1+} = f(1). By the denition ofcontinuity then, f is continuous at these points. Now, youve alreadyestablished that f is continous everywhere else, so f is continouson its natural domain. Dene the function f from (-inf,0] U [1,inf) to (-inf, inf) asfollows:> f(x)=x for x<=0> f(x)=x-1 for x>=1> If you examine the endpoints of the half open intervals, youll see that> lim_{x->0-} f(x) = f(0), and lim_{x->1+} = f(1). By the denition of> continuity then, f is continuous at these points. Now, youve already> established that f is continous everywhere else, so f is continous> on its natural domain....hmm, not its natural domain > Dene the function f from (-inf,0] U [1,inf) to (-inf, inf) as> follows:>> f(x)=x for x<=0>> f(x)=x-1 for x>=1>> If you examine the endpoints of the half open intervals, youll see that>> lim_{x->0-} f(x) = f(0), and lim_{x->1+} = f(1). By the denition of>> continuity then, f is continuous at these points. Now, youve already>> established that f is continous everywhere else, so f is continous on>> its natural domain.> > ...hmm, not its natural domainWhoops.. Yes, a domain is specied in this case. So, f is continuous onits domain. Dene the function f from (-inf,0] U [1,inf) to (-inf, inf) as follows:> f(x)=x for x<=0> f(x)=x-1 for x>=1> Clearly this function is continuous over> each of the two disjoint intervals which make up its domain.> But does it make sense to call the function continuous?> (Its the gap in the domain that bothers me.)The function f is continuous at every point (number) in itsdomain, everywhere f is dened. That is the denition ofwhat it means for a function to be continuous.For a function f not to be continuous, there has to be anumber in its domain where f is not continuous. Dene the function f from (-inf,0] U [1,inf) to (-inf, inf) as follows:f(x)=x for x<=0f(x)=x-1 for x>=1Clearly this function is continuous over each of the two disjoint intervals>which make up its domain.But does it make sense to call the function continuous? Whether or not it makes sense to call it that, the given function_is_ continuous.>(Its the gap in>the domain that bothers me.)>L************************David C. Ullrich > Whether or not it makes sense to call it that, the given function> _is_ continuous.> > You havent been reading elementary calculus texts recently, haveyou...???Of course a mathematician will say it is continuous. But theirdenition may not agree with the denition in all elementary texts. =Leonard M. Wapner scribbled the following:> Dene the function f from (-inf,0] U [1,inf) to (-inf, inf) as follows:> f(x)=x for x<=0> f(x)=x-1 for x>=1> Clearly this function is continuous over each of the two disjoint intervals> which make up its domain.> But does it make sense to call the function continuous? (Its the gap in> the domain that bothers me.)AFAIK you can safely call the function continuous. Or at least call itcontinuous on the interior of its domain and one-sidedly continuousat 0 and 1.-- /-- Joona Palaste (palaste@cc.helsinki.) ------------- Finland ---------- http://www.helsinki./~palaste --------------------- rules! --------/It was, er, quite bookish. - Horace Boothroyd > Its ludicrous to try to justify teaching mathematics,>> because its useful. For example, consider factoring>> polynomials, etc. Mathematics is part of Western>> Civilization. In order to be educated or cultured,>> if one values that, it is an important subject to be>> acquainted with. Its useful and valuable for those>> who use and value it.>> [...]>> I presume you consider it as an argument that an>> average fourth-grader wouldfind convincing?>If fourth graders are pressing for an answer to this>question, it means the class is not going well.>Engaged fourth graders do not ask such questions.It does not mean that at all; it means something MUCHworse. The educationists try to teach relevant factsand methods, and do not give any of the concepts behindthose facts and methods. Younger children do not havethis problem; they want to know why something is thecase. By fourth grade, they have largely had thisknocked out of them, and VERY few of those involved withthe public schools have any understanding; this is whythe new math failed, as the TEACHERS could not learnwhat the children could.Mathematical CONCEPTS and the purely linguistic use ofvariables belong early. College students today havehad little, if any, of this, and want to be taught HOW to solve well-formulated problems. This is almostirrelevant, as computers can do this. They need to beable to speak mathematics, not to do the grunge work.I have had a class of prospective high school teacherswith two years of calculus 75% of whom could not setup the calculus to do probability problems on a takehome exam, problems similar to homework. Students memorize denitions and formulas, but understandlittle. On one midterm, power series were multipliedterm by term.Scientists of all types, and even historians andstudents of linguistics and literary style, make use of this; they do not have to be able to carryout the calculations, but they need to be able tospeak the language, so that those who are familiarwith the methodology can put their problems on thecomputer, and criticize what can go wrong.In addition, mathematical approaches are even usedin professional athletic training. Pitching coachesuse the computer and digitized tapes to analyze pitching style and make recommendations, and thisis similar to what is done in track and elsewhere.-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University > > Who proved that an innite number of numbers (i.e. innite series)>> > can have a nite sum?>> No one proved that.>> Someone dened it.>> All right, instead of proved lets substitute observed and answer>> the OPs intended question.>book (Grossman: Multivariable Calculus, ...):> The basic idea in the study of innite series is that an> innite number of numbers can have a nite sum. This> concept may seem natural now, but it took mathematicians> over two thousand years to come grips with. -- Aristotle --> denied that such a [innite] sum could exist.>So does that mean people didnt understand at the time of Aristotle>that an innite sum (i.e. innite series) could have a nite sum?Aristotle could handle Euclid (Aristotle was beforeEuclid), but he had difculties like that. He couldnot handle the idea that a point could be an elementof a line and also divide the line.-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University Who proved that an innite number of numbers (i.e. innite series)>can have a nite sum?This goes back to the Greeks; they were the rstto prove anything. The Achilles and the tortoiseparadox was known to be a paradox of that type.-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University > proofs>> why do authors usually consider the proofs so important in mathematical>> texts ?>> Isnt it usually better when only a few people read and check the proofs,>> while the masses just try to grasp the meaning of the text>> omitting the proofs ?>> The proofs could be included as an appendix at the end of>> the papers, if necessary, IMO.>> --Guenter Stertenbrink>If the proofs are well-crafted and eloquent and the reader is reasonably >well prepared, it shouldnt be a burden to read proofs.Not only that, the proofs can help understand the theorems.-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University how many % of his time should the average>reader spend on reading proofs>in a math paper ?>please give your opinions.>I start with : 30%It can vary between near 0 and almost 100%. Sometimes,the proofs are obvious; much of mathematics consistsof seeing the obvious, with the proofs being verystraightforward. But some papers are concerned with adifferent method of proof of a standard theorem, or anextension of it, and getting at least enough of an ideaof the proof to nish it oneself is the real goal ofreading the paper.-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University > proofs>> why do authors usually consider the proofs so important in mathematical>> texts ?>Because that is what mathematics is without.The only way we know things is if there are proofs. Also,the proofs often have the insight into the problem, and IMOit is better to have a proof which indicates what is goingon in the theorem, and derives the results in a directmanner, rather than a cute proof which is quick anddisguises matters. Unfortunately, there are cases in whichsuch proofs do not exist.>> Isnt it usually better when only a few people read and check the proofs,>No. If you refuse study proofs then you are cravenly deferring to authority.There are cases where the proofs are sufciently long anddetailed that this might be the case, but even then oneshould know the ideas of the proof. >-- >Robin Chapman, www.maths.ex.ac.uk/~rjc/rjc.html>Needless to say, I had the last laugh.> Alan Partridge, _Bouncing Back_ (14 times)-- This address is for information only. I do not claim that these viewsare those of the Statistics Department or of Purdue University.Herman Rubin, Department of Statistics, Purdue University =Is anyone aware of any technique for computing cycle numbers of bigsubgroups H of S_k, if we know the generators of H. What Im interested inis applying Polyas theorem to big subgroups (e.g. C_2 wr (S_n,n) as asubgroup of S_{n(n-1)/2})Alex. >>>Right. The middle coefcient in this case is>> (-3x + sqrt(-7x^2 - 8x))/4> > Well I put that up kind of curious that someone might ll it in, but> you failed badly here Decker, as my rst check was at x=1.> > > a^2 - 7(1^2 + 1) = a^2 - 14, so a=+/-sqrt(-14).> > Now then, dividing off 7, should then give b=+/-sqrt(-2).>No. See below. > But with your claims, you get> > b^2 + (-3 + sqrt(-15))b/4 - 2 = 0.> Right, thats what I get. Heres how. Your specicationwas that you wanted two functions, b_1(x) and b_2(x)which satisfy P(x)/7 = 25x^2 + 30x + 2 = (5b_1(x) + 1)(5b_2(x) + 2) [1]and which are roots of b^2 + C(x)b + (x^2 + x) [2]Where C(x) is to be found.I remind you that those are your requirements, as stated above.[Note in passing that there are innitely many other bsone could pick, but in each case youd have a differentpolynomial for which they would be roots.]At any rate, since [2] is dened by (b - b_1(x))(b - b_2(x)) = b^2 + C(x)b + (x^2 + x)we must have b_1(x)b_2(x) = x^2 + xand -(b_1(x) + b_2(x)) = C(x).Expand the RHS of [1] and we have 25x^2 + 30x + 2 = 25b_1(x)b_2(x) + (2b_1(x) + b_2(x))(5) + 2 = 25(x^2 + x) + (2b_1(x) + b_2(x))(5) + 2so, rewriting the LHS and subtracting 2 from both sides we have 25(x^2 + x) + 5x = 25(x^2 + x) + (2b_1(x) + b_2(x))(5)so 2b_1(x) + b_2(x) = xfrom which we have b_2(x) = x - 2b_1(x)Since we have your requirement on the product of the bswe must have x^2 + x = b_1(x)b_2(x) = b_1(x)(x - 2b_1(x))so (b_1(x))^2 - xb_1(x) + (x^2 + x) = 0, which wecan solve for b_1(x): b_1(x) = (x + sqrt(-7x^2 - 8x))/4(picking the positive multiplier of the square root),from which we obtain b_2(x) = (x - sqrt(-7x^2 - 8x))/2so C(x) = -(b_1(x) + b_2(x)) = (-3x + sqrt(-7x^2 - 8x))/4as I had originally. Notice that this is a necessary conclusion(well, up to sign) of your two requirements.Now, you seem to be surprised that b_1(x) isnt a_1(x)/7, buttheres no reason to expect it to be. Observe that I originallyhad P(x) = 7(25x^2 + 30x + 2) = (5a_1(x) + 7)(5a_2(x) + 7)and you wanted me to produce the factorization P(x)/7 = 25x^2 + 30x + 2 = (5b_1(x) + 1)(5b_2(x) + 2)which I did. Look at what you asked for, *with 2 as the constantterm of the second factor*. It should come as utterlyno surprise that, because of the different constantsin the last terms, wed wind up with b_1(x) differentfrom a_1(x)/7. Ill note in passing that you can indeedobtain a factorization with b_1(x) = a_1(x)/7 and 7instead of 2 for the constant in the last term butIll leave that for the reader, observing only thatits not pretty. Now lets return to our scheduledbroadcast. Lets see.> > Maybe Decker came out hurriedly, probably in a defensive reaction, and> tossed something out there.> > Even if his quadratic ts as a factorization, its not THE> factorization that was being looked for as Ive just shown. Remember,> there is no uniqueness of polynomial factorization here, so there are> an innity of factorizations.>Of course. All I did was produce what you asked for. > Still Decker might seemingly get *some* credit, if he found one of> them.> > He fails at the task at hand though for notfinding what follows from> the as in his *own* example.> > Remember the question Im raising is what happens when 7 is divided> from both sides of> > (5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2)> > and Im using Deckers own example, primarily because its dramatic to> do so, and because its a *quadratic* so that I can show how complete> his failure is, with something so seemingly simple.>Hey! I thought you said Id get partial credit. Cheater. :-) > Moving on, theres the question of why did Decker pick his example. My guess is that its because at x=1 *both* as have sqrt(7) as afactor.>>Precisely. My point being that the constants dont serve as>>indicators of how things are to be divided in any but the x = 0 case.> > But Decker, how do you suppose *constants* like 7 can change dependent> on x?>Obviously, they dont. The whole point was that the factorizations do.Ill state again that you have no reason to infer what happens ina factorization for x != 0 from what happens when x = 0. > Now then, why dont you explain where you got your factorization from,> like the techniques you used to generate it?> Always glad to oblige. See above. >Its worth noting, by the way, that if we take x = 2>>we have a situation where you cant even split the factor>>of 7 into anything as nice as sqrt(7) * sqrt(7).> > Why? Can you elaborate more on why you think that is the case, and> why you think its worth noting?> Because it shows how factorizations in the algebraic integersare very much stranger than factorizations in rational integers.Rick > > Theres one type of attempt at disputing my work that Ive seen pop up> > regularly, and it popped up today from Rick Decker, a professor at> > Hamilton University, > > > To be precise, the legal name is Hamilton *College*. We do have> a university--Colgate--just down the road, but were a college.> (Ill let maky make of that what he will.) In fairness, its> a common error, especially in most of the rest of the world,> where college means something entirely different than it> does in the US.> > Ok, my mistake, so its Hamilton College then.> > > so I thought Id talk about it in detail. Here> > are some headers so you canfind the post:> > > > In his post Decker claimed to mirror my argument using a quadratic> > instead of a cubic, where he has> > > > (5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2) > > > > where his as are roots of > > > > a^2 - (x - 1)a + 7(x^2 + x).> > Checking at x=0 reveals that the actual constant terms of the> > factorization are 7 and 2, where Decker picked a_1(0) = 0 at x=0.> > > > Now then, consider what happens if you divide both sides of> > > > (5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2) > > > > by 7, as then you end up with something like> > > > (5b_1(x) + 1)(5b_2(x) + 2) = 25x^2 + 30x + 2> > > > where the bs are roots of some unknown quadratic, though the rst> > and last coefcients ARE known:> > > > b^2 + ? b + (x^2 + x).> > > > Now then, its just a quadratic people. SOME mathematician in all the> > world should be able to give what the middle coefcient is, right?> > > > Right. The middle coefcient in this case is> > (-3x + sqrt(-7x^2 - 8x))/4> > Well I put that up kind of curious that someone might ll it in, but> you failed badly here Decker, as my rst check was at x=1.> > > a^2 - 7(1^2 + 1) = a^2 - 14, so a=+/-sqrt(-14).As pointed out in a reply to this post that is wrong.It should be a = +/-sqrt(14). > Now then, dividing off 7, should then give b=+/-sqrt(-2).Should give b=+/-sqrt(2).> > But with your claims, you get> > b^2 + (-3 + sqrt(-15))b/4 - 2 = 0.> > > > Lets see.> > Maybe Decker came out hurriedly, probably in a defensive reaction, and> tossed something out there.And so far he hasnt answered from what is currently showing in Google Groups.James Harris > > > Theres one type of attempt at disputing my work that Ive seen pop up> > regularly, and it popped up today from Rick Decker, a professor at> > Hamilton University, > > > > > > To be precise, the legal name is Hamilton *College*. We do have> > a university--Colgate--just down the road, but were a college.> > (Ill let maky make of that what he will.) In fairness, its> > a common error, especially in most of the rest of the world,> > where college means something entirely different than it> > does in the US. Ok, my mistake, so its Hamilton College then.> > > so I thought Id talk about it in detail. Here> > are some headers so you canfind the post:> > > > > > In his post Decker claimed to mirror my argument using a quadratic> > instead of a cubic, where he has> > > > (5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2) > > > > where his as are roots of > > > > a^2 - (x - 1)a + 7(x^2 + x).> > > > Checking at x=0 reveals that the actual constant terms of the> > factorization are 7 and 2, where Decker picked a_1(0) = 0 at x=0.> > > > Now then, consider what happens if you divide both sides of> > > > (5a_1(x) + 7)(5a_2(x) + 7) = 7(25x^2 + 30x + 2) > > > > by 7, as then you end up with something like> > > > (5b_1(x) + 1)(5b_2(x) + 2) = 25x^2 + 30x + 2> > > > where the bs are roots of some unknown quadratic, though the rst> > and last coefcients ARE known:> > > > b^2 + ? b + (x^2 + x).> > > > Now then, its just a quadratic people. SOME mathematician in all the world should be able to give what the middle coefcient is, right?> > > > > > Right. The middle coefcient in this case is> > > > (-3x + sqrt(-7x^2 - 8x))/4> > Well I put that up kind of curious that someone might ll it in, but> you failed badly here Decker, as my rst check was at x=1.> > > a^2 - 7(1^2 + 1) = a^2 - 14, so a=+/-sqrt(-14).> > As pointed out in a reply to this post that is wrong.> > It should be a = +/-sqrt(14).> No - the expression is a^2 - (x - 1)*a + 7*(x^2 + x).When x = 1, this reduces to a^2 + 14, which has roots+/- sqrt(-14).> Now then, dividing off 7, should then give b=+/-sqrt(-2).> > Should give b=+/-sqrt(2).> > > But with your claims, you get> > b^2 + (-3 + sqrt(-15))b/4 - 2 = 0.> > > Lets see.> > Maybe Decker came out hurriedly, probably in a defensive reaction, and> tossed something out there.> > And so far he hasnt answered from what is currently showing in Google Groups.> Why should he answer? He got it right the rst time. Hehas nailed you cold. What your method would yield in thiscase is the factorization Q(x) = (5 a_1(x) + 7)*(5 b_1(x) + 2)where b_2(x) = a_2(x) + 1 and a_1(x) and a_2(x)are the roots of a^2 + (x - 1)*a + 7*(x^2 + x).One notes that a_1(0) = 0, a_2(0) = -1, b_2(0) = 0.Thus Q(0) = 14 = 7*2. YOUR method would dictate that you factor Q(x)/7 as Q(x)/(7 * 1) = (5 a_1(x)/7 + 1)*(5 b_2(x) + 2),which yields, exactly as in your cubic case,the fact that in general a_1(x)/7 is not an algebraicinteger: for x = 1, a_1(x) = sqrt(-14) andsqrt(-14)/7 is not an algebraic integer. But, Decker points out, for x = 1, thereis *another* way to factor Q(x)/7 that DOESresult in algebraic integers all around: Q(1)/7 = Q(1)/(sqrt(7)*sqrt(7))) = (5*sqrt(-2) + sqrt(7)) * (-5*sqrt(-2) + sqrt(7)). You can check that this equals 57, as it should. Bottom line: your factorization doesntwork. Deckers does. And it generalizes for otherx <> 0. Try x = 2 as Rick suggests. It is exactly the same in the cubic caseexcept there, the roots of the equation area mess to write down and the corresponding factorizationof 49 is even worse. That is why we have had toresort to more abstract arguments. The beautyof Ricks example is that you can do the calculations- no too-hard-for-you-to-understand abstract argument is required - and even you cannot deny the result. Your *method* is bogus. [In your cubic example, yourfactorization of 49 as 7*7*1 is the wrong one, exactlyanalogous to what happens here, where your factorization of 7 as 7*1 is the wrong one.] Deckers example leaves you oundering around with arithmetic errors and your usual bluster - and nothing else. Bravo, Rick Decker! Nora B.> > James Harris > > a^2 - 7(1^2 + 1) = a^2 - 14, so a=+/-sqrt(-14).> > If Harris means for a^2 - 14 to be zero, he should take> > a = +/-sqrt(14), not sqrt(-14)OOPS! Youre right. Ok, I had yet another sign error.> > Now then, dividing off 7, should then give b=+/-sqrt(-2).> > > In true mathematics, sqrt(-14)/7 is not equal to sqrt(-2),> > nor is sqrt(14)/7 equalo to sqrt(2).> > If Harris means to divide sqrt(-14) by sqrt(7), he must say so > unambiguously.> > And it would be helpful if he were to clean up his own Augean stables > before sneering at others stables.Well you got the latter wrong as remember there are *two* results, soeach is divided by sqrt(7).James Harris =I am posting this as more a fun challenge rather than a seriousquestion.{So, that is why I have cross-posted this to rec.puzzles ANDsci.math.}We almost all are aware that, for n = integer >= 2, we can write anon-integer real with base-n digits (0 through {n-1}), some digitsfollowing after a decimal-point if necessary.But what about in base-1?Integers are easy (though base-one representations are not exactlyanalogous to higher bases, since we do not write base-1 integers usingonly zeros).Example: 7 (base 10) =1111111 (base 1)But what about non-integers?Have you any clever schemes for writing, say, 1/2 or pi in base-1??[The best I can come up with right now is to write the continuedfraction of the real, with each term consisting of a base-1 positiveinteger. But this is really a Quet But what about in base-1? Integers are easy (though base-one representations are not exactly> analogous to higher bases, since we do not write base-1 integers using> only zeros). Example: 7 (base 10) 1111111 (base 1) But what about non-integers?> Have you any clever schemes for writing, say, 1/2 or pi in base-1??>2/2 = 0.111111...1/2 = 0.1010...1/3 = 0.100100...2/3 = 0.110110...1/4 = 0.10001000...2/4 = 0.10101010...3/4 = 0.11101110......> [The best I can come up with right now is to write the continued> fraction of the real, with each term consisting of a base-1 positive> integer. But this is really a list of base-1 integers. Still,> anything better??]>Huh? But what about in base-1? Integers are easy (though base-one representations are not exactly> analogous to higher bases, since we do not write base-1 integers using> only zeros). Example: 7 (base 10) 1111111 (base 1) But what about non-integers?> Have you any clever schemes for writing, say, 1/2 or pi in base-1?? 2/2 = 0.111111...> 1/2 = 0.1010...> 1/3 = 0.100100...> 2/3 = 0.110110...This also isnt an intuitive scheme (IMHO), since then what is ?/? = 0.011011...Also 2/3? Then we have two different representations for thesame number (and 3 different ways to write 3/4, and 7 differentways to write 7/8, and 10000 different ways to write 10000/10001,and so on). Hmm.> [The best I can come up with right now is to write the continued> fraction of the real, with each term consisting of a base-1 positive> integer. But this is really a list of base-1 integers. Still,> anything better??] Huh?For example, 1/2 = 1/(2+0) -> (11) 3/4 = 1/(1+1/(3+0)) -> (1,111) pi = 1/(3+1/(7+1/(15+... -> (111,1111111,111111111111111,1,...)HTH,-Arthur Example: 7 (base 10) 1111111 (base 1)... and just for fun, given that usually numbers in base N are writtenusing alpha-numeric digits 0 to (N-1), whereby symbols representingdigits N >= 10 are A, B, C etc or any other representation. Myquestion is, why in base N=1, we do not write:7 (base 10) = 0000000 (base 1) ? > We almost all are aware that, for n = integer >= 2, we can write a>> non-integer real with base-n digits (0 through {n-1}), some digits>> following after a decimal-point if necessary.>> >> But what about in base-1?and Mensanator (or should it be THE Mensanator?) replied:> There is no Base 1. ...> ...> Now if you want to talk about non-standard number systems, thats ne,> but dont interchange them with standard systems because they dont> mix well.Can we use a fraction as a radix, such as r = 3/2? And if so, what happenswhen r approaches 1?I havent looked at fractional radices, so I dont know whether its ameaningful question. Issues would seem to be the ability to represent allnumbers (uniquely?), and what it means for a rational to approach 1.Bob H Have you any clever schemes for writing, say, 1/2 or pi in base-1??1/2 = 1.112/3 = 11.111pi = 1111111111111111111111111111111.1111111111 Have you any clever schemes for writing, say, 1/2 or pi in base-1?? 1/2 = 1.11> 2/3 = 11.111> pi = 1111111111111111111111111111111.1111111111 Ah, but this is but an approximation to pi! That wont do!The *real* tally-representation of pi is, as in decimal, an innitesequence, like this: ...111111111111111111111.11111111111111111...This sort of thing can be tedious to write out, of course, andrequires innite amounts of paper to do sums with; so certainscholars have taken the ingenious approach of folding thenumber at the position of the unary point and interleaving thedigits of the numerative and denominative parts, like so: .1 1 1 1 1 1 1 1 1 1... 1 1 1 1 1 1 1 1 1...or more concisely as .11111111111111111...This has the advantage of being manipulable almost as readilyas the standard representations. For example, a multiplicationby two is obtained by halving the frequency of denominative 1sin the representation: .11111111111111111...and addition can be performed on any common household typewriterwith an overstrike capability. In short, the tally-system of real number representation isperfectly suited to arithmetic on all levels, and I think youllagree that it may become the wave of the future in mathematicseducation.;-)-Arthur[FWIW, Mensator was right on target.] =In usual bases (>1), 0 (within a non-zero number representation) isa place marker. To the left of the decimal point, the representationstops with a non-zero integer. To the right it is somewhat freeform. In any case, how can you represent any number at all in base1?---= 19 East/West-Coast Specialized Servers - Total Privacy via Encryption =--- >I have a question and would appreciate any help.>Let (f_n)_ be a sequence of real valued functions dened on [a, b]>that converges uniformly to f. For every x in [a,b], let F_n(x) Integral (from a to x) f_n(t)dt. > > You have to say a little more than you have or this integral> doesnt even exist. Possibly you meant to assume that f_n> was continuous - that would do it.> >Then, (F_n) converges to F(x) Integral (from a to x) f(t)dt. Is this convergence uniform on [a,b]?> > Yes.Presumably he meant to assume the f_n are Riemann integrable--theminimum needed to make sense of Integral (from a to x) f_n(t)dt. The uniform limit of Riemann integrable functions is also Riemannintegrable, so this seems OK.--Ron Bruck =JS: Yes and he is correct.PZ: Einsteins stated position was that gravitation and frame acceleration arecompletely physically equivalent.How can you now say this is correct? Even Wheeler doesnt believe this.JS: Show me quote from Wheeler that leads you to say that.I gave you complete argument based on geodesic deviation equation and the complementarityof g-force vs tidal measurements! Thats it.You need, in addition, curved geometry to make LOCAL EEP consistent GLOBALLYthis is the point of Hawkings example where two oppositely accelerating observers are atxed spatial separation. This is not possible in at Minkowski space-time only in non-Euclideancurved space-time. This is why Yilmaz and PV are complete nonsense IMHO.PZ: For some reason it seems you just cant bring yourself to admit that Einsteincould be wrong about this fundamental issue, regardless of all the obviousobjections.JS: Einstein is not wrong. He is wonderfully consistent. The idea here is subtle.PZ: Is Einstein infallible?JS: On this, yes.Overheard at Caffe Trieste:Alice: Do you know the difference between God and Jack Sarfatti?Bob: No, what is it?Alice: God does not think he is Jack Sarfatti. ;-) > > JS: Yes and he is correct.> > PZ: Einsteins stated position was that gravitation and frame > acceleration are> completely physically equivalent.> > How can you now say this is correct? Even Wheeler doesnt believe this.> > JS: Show me quote from Wheeler that leads you to say that.> > I gave you complete argument based on geodesic deviation equation and > the complementarity> of g-force vs tidal measurements! Thats it.> You need, in addition, curved geometry to make LOCAL EEP consistent GLOBALLY> this is the point of Hawkings example where two oppositely accelerating > observers are at> xed spatial separation. This is not possible in at Minkowski > space-time only in non-Euclidean> curved space-time. This is why Yilmaz and PV are complete nonsense IMHO.> > PZ: For some reason it seems you just cant bring yourself to admit that > Einstein> could be wrong about this fundamental issue, regardless of all the obvious> objections.> > JS: Einstein is not wrong. He is wonderfully consistent. The idea here > is subtle.> > PZ: Is Einstein infallible?> > JS: On this, yes. Overheard at Caffe Trieste:> > Alice: Do you know the difference between God and Jack Sarfatti?> Bob: No, what is it?> Alice: God does not think he is Jack Sarfatti. ;-)[EL]Exactly. :-)EL Let s(r,m) > ---> r> > k> /> ---> k|m> 1<= k <= sqrt(m)> > (which is, in linear-mode)> > sum{k|m,1<= k<= sqrt(m)} k^r.> > So, we have s(r,m) is > the sum of the r-powers taken over the lower half of the positive> divisors of m.> > For example, s(1,m) is:> http://www.research.att.com/cgi-bin/access.cgi/as/njas/ sequences/eisA.cgi?Anum=A066839> > > If r is > 0 (r = any *positive* real), then:> > > limit{m -> oo} > m> ---> 1 > ------- > s(2r,k) m^(r+1) /> ---> k=1> > > 1> ---------- (?)> 2 r (r+1)> > > Linear-mode:> > limit{m->oo} > (1/m^(r+1)) sum{k=1 to m} s(2r,k) = > > 1/(2 r (r+1)) (?)> > (I am err-prone today, so I hope I thwarted fate...)> > Example: If I am right, the sum of the rst m terms of the EISs> A066839 divided by m^(3/2) approaches 2/3.By the way,If s(r,m) is such that, for q = integer >= 2,--- r > k/---k|m1<= k <= m^(1/q)(which is, in linear-mode)sum{k|m,1<= k<= m^(1/q)} k^r ;then (?):limit{m -> oo} m --- 1 ------- > s(qr,k) =m^(r+1) / --- k=1 1---------- q r (r+1)Linear-mode:limit{m->oo} (1/m^(r+1)) sum{k=1 to m} Quet =Am I right to assume:limit{n-> oo} (1/(n ln(n))) sum{j=1 to n} (sum{k|j, k<= sqrt(j)} H(k) )- (1/8) ln(n) = 1/4 + c/2,where H(k) = 1 + 1/2 + 1/3 +..+1/k, the k_th harmonic number,and where c = Eulers contstant (c = following optimization problem, which has twooptimization objectives:Find the lowest metric B approach, which can yield the highest metric A...A and B are two metrics...Is there any certain techniques for handling such multi-objectiveoptimization problem? I wonder if some common optimization techniques suchas steepest decent, or Newtons minimization, still work or not...Please give me some pointers!-Wlalal > Is there a closed form for this sum: i=n> SUM x^(gcd(i,n))> i=1> > (Note: This arises in counting the number of essentially distinct> colorings of a directed cycle of length n).> > SiamakI do not know, but &rnum=19&prev=I get a result which can be used tofind that your sum is also:sum{k|n} phi(n/k) x^k.(this sum is over the positive divisors, k, of n; and phi(m) is theEuler phi function, the number of positive integers <= m and coprimewith m {= n /k}.)So, my sum basically gives the Quet optimization problem. In designingiter?6hlistrecoHptxelongfnt#shorfontTEXTGenevaptszfixd8listrecopjste numleft(FISHÊGeneva??. 7?1.01.01.01.0???????6!{?Ec frWEst~WEpf?ru?P¢stylnüISH?TABS?WDTH¸jstf?rct?lct?PRopB Kco[YAcute]?&???&?[YAcute]?x&?ü[YAcute]???h[YAcute]?[Capital AGrave]&??[YAcute]??&??[YAcute]?????? !?0[YAcute]?!?¬[YAcute]?!??[YAcute]?!?-[YAcute]?&!?d[YAcute]?2!?, [YAcute]?x!?üven integer; some of as and bs should be multiple of 3s...Moreover, the number of nonzero as and bs should be as small aspossible...Under the above-mentioned conditions, I need tofind the best of suchconstructions...This is simplied statement, the problem is more complex and n is a lotlarger... which make the exhaustive search very timeconsuming... even forfast computers...Please tell me how to systematically design algorithm to handle this kind ofdiscretely constained optimal matrix construction problem? Or please give mesome pointers!-Wlala =1) In my textbook there is an unproved proposition (the proof is saidto be obvious) which states that function f: X subset R -> R isdifferentiable at point a in X if and only if there exist A = lim_{x-> a+} ((f(x) .9a f(a)) /(x-a)), B = lim_{x -> a-} ((f(x) .9a f(a))/(x-a)) and A = B. I do not understand this, given that the textbookdenition of the derivative of function f at point a does not requirea to be interior. Does the statement of the theorem imply that thecondition of point a being interior is implied in the denition ofthe derivative or I miss something? In short, what must the derivativedenition look like for this theorem to hold true?2) Which conditions are needed so that differentiability at a pointwould imply differentiability on some interval embracing the point?3) What are the most common and accepted precise denitions of theconditions of a function to be continuous at a point and to bedifferentiable at a point? Consider identity function f: [0,1] ->[0,1]. Is it continuous at 0? Is it differentiable at 0? (according tothe denitions you provide). 1) In my textbook there is an unproved proposition (the proof is said> to be obvious) which states that function f: X subset R -> R is> differentiable at point a in X if and only if there exist A = lim_{x> -> a+} ((f(x) .9a f(a)) /(x-a)), B = lim_{x -> a-} ((f(x) .9a f(a))> /(x-a)) and A = B. I do not understand this, given that the textbook> denition of the derivative of function f at point a does not require> a to be interior. Does the statement of the theorem imply that the> condition of point a being interior is implied in the denition of> the derivative or I miss something? In short, what must the derivative> denition look like for this theorem to hold true?> > 2) Which conditions are needed so that differentiability at a point> would imply differentiability on some interval embracing the point?> > 3) What are the most common and accepted precise denitions of the> conditions of a function to be continuous at a point and to be> differentiable at a point? Consider identity function f: [0,1] - [0,1]. Is it continuous at 0? Is it differentiable at 0? (according to> the denitions you provide).> Consider X as the set of rationals, then X does not have any interior points (as a subset of R), but functions from X to R can still have derivatives.On the other hand, The function f(x) = sqrt(x^3) from the non-negative reals to the reals clearly has a derivative at x = 0. So that the if-and-only-if fails, at least for many dentions of derivative.The precise wording of the denition of derivative in your text may be critical to the issue. =It looks like George beat me to the essential idea. Mine is simpler, but there is conceptual common ground.We knew each other in 1966-7 in the UCSD group Greg Benford describes in Timescape that included Herbie Bernstein.George came down from Cal Tech frequently in his black AC Shelby Cobra that I used to ride around in with him when Iwas not in Harry Yesians Red Corvette. This was the era of American Gratti.Indeed it was because of George that I got the job at SDSU andmet Fred Wolf. The story is in my book Destiny Matrix.Chapline on vacuum etc. from 1999:The Vacuum Energy in a Condensate Model for SpacetimeAuthor: George Chaplinehttp://www.arxiv.org/abs/hep-th/9812129Comments: Postscript, 10 pagesJournal-ref: Mod.Phys.Lett. A14 (1999) 2169-2178It is shown that a simple model for 4-dimensional quantum gravity based on a3-dimensional generalization of anyon superconductivity can be regarded as adiscrete form of Polyakovs string theory. This suggests that there is auniversal negative pressure that is on the order of the string tensiondivided by the square of the Robertson-Walker scale factor. This is inaccord with recent observations of the brightness of distant supernovae,which suggest that at the present time there is a vacuum energy whosemagnitude is close to the mass density of an Einstein-de Sitter universe.http://www.arxiv.org/abs/hep-th/9807175The Black Hole Information Puzzle and Evidence for a Cosmological ConstantAuthor: George ChaplineComments: postscipt, 7 pagesRecent hints from observations of distant supernovae of a positivecosmological constant with magnitude comparable to the average density ofmatter seem to point in the direction ofa two uid model for spacetime; where the normal component consists of ordinary matter, while thesuperuid component is a zero entropy condensate.My idea is not quite the same. The normal component consists of dark energy and dark matter both from residual zero point energy exotic vacua. Ordinary matter is ultimately made from vortex cores of attractive dark matter of strong short range positive quantum pressure where the superuid component drops to zero./zpf ~ - 1/Lp*^2 when vacuum coherence vanishes inside the stringy vortex core topological defects of the U(1) vacuum coherence order parameterLp* ~ 1 fermiLp*^2 = hG*/c^3G*/c^4 = (lepto-quark string tension )^-1 = It looks like George beat me to the essential idea. Mine is simpler,> but there is conceptual common ground. [...]If sheer sustained effort and commitment guaranteed results, I dontdoubt that Jack Sarfatti (and JSH) would be up there with Newton andEinstein. Heres an image of Jack: http://www.thinking-allowed.com/1jsarfatti.html-------------- ------------------------------------------------------------- John R Ramsden (jr@adslate.com)--------------------------------------------- ------------------------------Eternity is a long time, especially towards the end. Woody Allen > 8-Basti.M. On Bessel Differential Equations. Submitted for publication> to solutions of Bessel Differential Equations. Submitted> for other day I found a parametric solution of the standardBessel ODE, in which x and y are quite complicated functionsof erf(x) and its integral, not that its any practical useto man or beast.I wonder if anyone has managed tofind a symbolic solution ofthe slightly more general Sturm-Liouville ODE with spectrumequal to the real roots of the Riemann-Siegel zeta function.---------------------------------------------------- -----------------------John R Ramsden (jr@adslate.com)--------------------------------------------- ------------------------------Eternity is a long time, especially towards the end. Woody Allen =[...]|>If we were talking about formal proofs, it would be appropriate to|>speak in hard-edged terms about the properties of the proof. But|>this is an informal proof.|>|>Take an analogous situation. Fermats proof of his conjecture for|>p=4 ts the standard mold of proof by innite descent. He shows|>that if it fails for some value of z, then it also fails for some|>smaller value of z. How wrong is it to say he was doing a proof by|>induction? Well, I tend to cover myself in situations like that by|>saying essentially a proof by induction, but I dont think its|>just plain wrong to call it a proof by induction when its|>essentially a proof by induction.|>|>Likewise, I dont think its just plain wrong to call a proof|>by proving the contrapositive a form of proof by contradiction,|>since its essentially a proof by contradiction.|>|>For one thing, if we were to take this informal proof (or any|>proof by proving the contrapositive) and convert it into a|>formal proof, quite typically it would formalize as a proof by|>contradiction.||We may be getting somewhere:||Depends on the formal system. Suppose we were talking|about a formal system that had this rule of inference:||[Contrapositive:]||~B |- ~A|_______| |- A -> B.||In that formal system a proof via the contrapositive would|formalize precisely as a proof via Contrapositive.Well, you could put together a system like that. People have been knownto write systems of logic that would do a lot more than just include aproof-by-contrapositive. I gather theres a logic textbook by a guy namedCopi which has several more ways of disguising proof by contradictionunder several more obscure names, each distinct from the other one.Proof by dilemma, etc. Not considered very elegant, though.One problem with adding proof by contrapositive as a special rule is thatits redundant. If we were to drop another rule, probably we could makeit stop being redundant, but then itd be essentially doing the job thatproof by contradiction had been doing.In the sequent calculus, one takes A1,...,An |- B1,...,Bmto mean (A1&...&An)->(B1 or ... or Bm). It appears typical enough to haveas rules in the sequent calculus things like these: S A |- T -------- S |- ~A T S |- A T -------- S ~A |- Tand sometimes the same rules taken in reverse, where S and T are listsof formulas and A is a single formula. In a system like that, one mighthave ~B |- ~A -------- ~B A |- -------- A ~B |- -------- A |- Bor ~B |- ~A -------- |- B ~A -------- |- ~A B -------- A |- Bwhere in the rst, the empty disjunction on the right hand side standsfor a contradiction, and in the second the empty conjunction on the lefthand side is simply taken to be true.Now, your rule of replacing the contrapositive with the implication islike this, except that it involves moving a statement from each side ofthe turnstile, |-, to the other side as one removes a negation from it.Requiring both moves to be made at the same time seems somewhat arbitraryto me. Each rule permitting each separate move of a statement to the otherside while removing a negation is okay, and it seems reasonable to meto think of the combined switcheroo as being composed of the two movestaken one at a time, in either order.The one rule says that deducing ~A from a set of premises is equivalentto deducing a contradiction from the set of premises together with A. Theother rule says that deducing a contradiction from a set of premises whichincludes ~B is equivalent to deducing B from the remaining premises. Thoseare the two standard forms of proof by contradiction, the rst being theconstructive one, the second being the standard way in which a proof failsto be constructive.The analysis is different in each system, but as far as I can see italways makes sense to consider it a combination of contradiction withsomething else small.I think partly I tend to think of proof by contradiction as being moreakin to an application of an axiom than as a pure inference rule. Thereis some arbitrariness in how one draws the line between inference rulesand axioms. There are systems which make mathematical induction aninference rule. There are systems which make everything except modusponens (from A, A->B infer B) into an axiom.If one were to append Zorns lemma and the well-ordering principle toZFC, one could say of a lot of proofs that they are not using the axiomof choice, but using the axiom of well-ordering. But that would be asomewhat strange and redundant axiomatization.Without turning Zorns lemma and the well-ordering principle into axioms,one could still reasonably categorize proofs in ZFC which are not proofsin ZF by the form of the axiom of choice, or the consequence of the axiomof choice, being used. Give me a pile of such proofs, and three binslabelled axiom of choice, Zorns lemma, and well-ordering principle,and I can probably put nearly every such proof unequivocally into one ofthe bins, by the principle *most directly* being used. (Well, some mightuse more than one.) (On sci.math, Matthew Wiener once quoted Herstein andKaplansky as writing that the axiom of choice is intuitively obvious,while as Zorns lemma its merely plausible, and as the well-orderingprinciple its obviously false.) This sort of categorization is probablypretty sharp.Yet for someone to say of all three piles, that they are proofs using theaxiom of choice, would be appropriate.I suspect one of the biggest disanalogies between this situation and thesituation with regard to proof by contradiction is that people dont tendto think of proof by contradiction as being application of an axiom.I offered an analogy with proof by induction versus proof by innitedescent, where I also could imagine on the one hand categorizing proofsas tting one or the other mold, but also wouldnt have much of a problemwith someone calling a proof by innite descent a kind of proof byinduction. There, one at least sometimes considers induction an axiom ots own, so maybe this makes people think of proof by induction as beingcloser to meaning proof which invokes the axiom of induction than toproof formatted in this form.A little bit of experience with constructive proof probably also helps tomake applications of proof by contradiction (i.e., direct or indirectapplications) stand out as special. If one has a proof which isconstructive aside from the passage from ~B->~A to A->B, one can callthat a constructive proof of A->~~B. A differently formatted proof whichis constructive aside from having proven the conclusion, B, bycontradiction can also be called a constructive proof of A->~~B. So inthat sense they are alike.The difference between a constructive proof of A->B and a constructiveproof of A->~~B, for mathematical statements A and B, is a naturaldifference in *mathematical* meaning, not just logical or proof-theoretic,not having to do with how condent anybody is with the correctness ofthe conclusion or what have you. Consider a linear transformation T on anite-dimensional vector space V. Think of your favorite proof that ifthe determinant of T is zero, then there exists a nonzero vector in thekernel of T. (What type of proof? Contrapositive or contradiction?)Presumably it will be in effect a proof that T mapping every nonzerovector in V to a nonzero vector leads to a contradiction. Why would Iexpect that? One can distinguish between situations in which one hasreached the existence of a nonzero vector in the kernel without any suchdetours, which enable us tofind such a nonzero vector in the kernel, andsituations in which one has arrived at this kind of contradiction, whichdont necessarily enable one tofind such a vector. The latter situationis not to be disparaged, necessarily; one can show that one can then atleast get a nonzero vector which maps under T to an arbitrarily shortvector, for example, which might be all that one wants. (And thedeterminant being nonzero is not necessarily enough to enable one tocompute a nonzero vector in the kernel. The problem case is when thetransformation is very close to the zero transformation.)Proving that if every nonzero vector maps under T to a nonzero vector,then the determinant is nonzero, is constructive. Whether one immediatelystates the contrapositive and proceeds that way, or whether one has proventhe existence of a nonzero vector in the kernel using contradictionanother way, leads you to a comm-110 Please help to solve these two problems. One member have posted thisproblem to a math group on msn. I have no idea to solve thisProblems are going like this:1. DigitsShow that for any natural n, at least one of two numbers, n or n+1,can berepresented in the following form: k + S(k) for a certain k, whereS(k) isthe sum of all digits in k. For instance, 21 = 15 + (5+1)2. Party!There is a group of people at a party. Show that you can introduce some of them to each other so that after the introduction, no more than two people in the group would have the same number of friends (initial conguration doesnt work because they all initially have 0 friends).Ajhar =I am posting a code which is written in c++ which canfind the bonacci seriesup to any n number .The code is like this://starting of the program#incluevoid main(){int number,f1=0,f2=1,temp=0;cout<>number;//the main logic is going like thiscout< equations. Unfortunately, I hardly know anything about numerical> analysis. So if you hava a program or idea how to solve it please> share with me.> The problem is the following:> C(1)=sum(j=1 to n){alpha(j,1)beta(j)prod(i=1 to k)[c(i)^alpha(j,i)]}> ...> C(k)=sum(j=1 to n){alpha(j,k)beta(j)prod(i=1 to k)[c(i)^alpha(j,i)])> where > prod(i= 1 to k)c(i)^alpha(j,i)=c(1)^alpha(j,1)*c(2)^alpha(j,2)...> I need to solve these equations for c(i). The alpha matrix is such> that the rst kxk part is a unity matrix.> Anybody, any suggestions?> greetings:> ZsoltI can do programming but i doest quit understand your problem will you explain your problem?Ajhar Im somewhat versed in math but no expert by far. Ive been browsing the> internet, news-groups and all, but still I have not found a good answer to> my question.> Im looking for a Java (J2ME) implementation (or something from which i can> create this implementation) for the approximations (only using additions,> subtractions, multiplications, divisions and mayb a square-root function and> logarithm) for one or both of these two functions:> exp(x) e^x (or pow(2,y), ... raising the power of 2 on> computers can be faster)> and/or> pow(x,y) x^y> where both x and(!) y can be real numbers (not necessarily integers).> The approximations need to be relatively fast (J2ME, MIDP1.0... limited> device capabilities, no oating-point support) but quite accurate.> Ive already have good implementations for the log(x) (using the Maclaurin> series for 1/(ln[x+1])) and squareroot(x) (using Newtons Iteration).> I need the approximations where y is between 0 and 1 and where y is a large> number:> (e^x = e^(largenum+fraction) = e^largenum * e^fraction)> PS: The x and y are real numbers represented in J2ME by a class representing> some form of xed-point values. approximate exp(x) =In the following Q=ln(2)= .69314718055994530942... and symbol [.] is devoted for integral part. Also x=[x]+{x}where {x} is fractionary part of x. First observe that 2^{a+N}e^{Z(a)}where N=integer:=[x/Q] , F:={x/Q} , Z(a)=(F-a)*Q ,a being an arbitrary real number. =Please verify (1): take logarithm in both sides.Suppose x >0 , let q be a positive integer and put k=[q*F] . Ifk/q =< F={x/Q} < (k+1)/q , select parameter a to be (2k+1)/(2q) . Then |Z(a)| =< Q/8 < 1/10 . Therefore using (1)(2) e^x=approx.=C(k)*2^N*G(Z(A))where G(z) will be a ,,good approximation of e^z for z small, e.g. for |z|<1/10 .==In the following I give such approximation G(z). Dene(*) A(z)=z^6 + 840*z^4 + 75600*z^2 +665280 B(z)= 42*z^4 + 10080*z^2 + 332640 H(z):= A(z)+ z*B(z). Then put = (3) G(z) = H(z)/H(-z) . = It may be shown that |(e^z - G(z))/e^z| =< 10^{-26} for |z|< Q/8 .In conclusion , tofind an approximation DEX(X) of e^X=exp(X) you can proceed as follows ( q=4 ) : STEP 1: Test the variable X , and determine T=|X| . Suppose that you work with real numbers in intervals (16^{-64},16^{63}). This means that you can approximate e^X only for X in [-175,175] .Dene (for instance) DEX(T)= .0996...E-76 if T =< -175 , DEX(T)=1 when T=0 and DEX(T)= .10035...E+77 when T>= 175 .STEP 2: Find N=[T/Q] , F={T/Q} .STEP 3: Find P=2^N , K=[4F] , A=(2K+1)/8 , Z=(F-A)Q .STEP 4: Select constant C , C:= 2^A , as a function of possible values of K ,K in{0,1,2,3} .STEP 5: Taking into account (3), consider approximation e^Z=approx = H(Z)/H(-Z) .STEP 6: Finding nal approximation, namely e^T=approx=C*P*G(Z)and DEX(X)= 1/(C*P*G(Z)) if Z is in (-175,0) , or DEX(X) = C*P*G(z) when X belongs to interval (0,175) . Note: Its possible to prove that the roots z_k of H(z) satisfy 2 =< |z_k| =< 42 ,therefore H(-z) =/=0 for |z| small ,e.g |z|< 2 . Other better functions that (*) are available.If you want tofind betterapproximations for e^z , please inform me. I appreciate that (1) was important. =Those who cant design, teach.Those who cant teach, design.And the rest are just clueless.Dan :-) And I keep stressing that I am talking about the U.S., of which youve> admitted some lack of knowledge.I said that I am not too familiar with US based research grants. Ialso said that I have no idea what the Fox news fan club is supposedto be. That is is where I admitted some lack of knowledge about theUSA, as you say.However I also said that: I know very well what publish or perish is(unjustied patronizing tone again, I note), William. I have somescientic publications, William, and we have pretty much the sameacademic system here in Israel, as in the USA (including gettingIn fact Ive spent some time in the USA academic system, in FortCollins C0. I am also quite familiar with the UK academic system, inaddition to the Israeli, of course. So, when I talk about the peoplefrom the academia, I know, it means quite a lot of people, from threedifferent countries, but having similar academic systems. That doesntmake my statements absolute, as you say. But, IMHO, they aresignicant enough in countering statements like:...but they often cant do any signicant research either. (Dependsreply to my: A Prof with a tenure that doesnt have much contractNote your rather strong words often and any. As to what looks likean insurance policy (or a sort of disclaimer) of Depends on...,well, it doesnt make much sense that the academic system and academicfreedom concepts should be signicantly different in, say chemistrydept from that of math, or biology. Even in the great USA. Well, ifsome mysterious reports they send back from the front lines... givea different picture, I guess, I am expected to accept them as factsabout the USA. Well, I might not do that, support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id hA6KGK001939; =Im desperately looking for an algorithm to put a reduciblenonnegative matrix in Frobenius canonical form by a symmetricpermutation of rows & columns. In graph-theoretic terms, this amountsto relabeling the graph nodes so that the absorbing nodes (or groups onodes) receive the highest labels. I will really appreciate it ifanyone out there can lend me a hand. Im desperately looking for an algorithm to put a reducible> nonnegative matrix in Frobenius canonical form by a symmetric> permutation of rows & columns. In graph-theoretic terms, this amounts> to relabeling the graph nodes so that the absorbing nodes (or groups o> nodes) receive the highest labels. I will really appreciate it if> anyone out there can lend me a hand.Look at Dulmage-Mendelsohn decomposition.For example in Matlab, help dmpermArnold Neumaier I am a student implementing a simple mode solver myself,> I need help.>> The one dimensional Helmholtz equation> d^2U(x)/dx^2+k^2(N(x)^2-n_eff^2)U(x)=0>> can be solved using Finite Difference method:czh, lets have an example of this BVP (boundary value problem).k^2 = 1.234^2N(x) = (x + 0.002345)n_eff^2 = 2.453x_0 = 0x_40 = 10n = 39y_0 = 0y_40 = -1.435h = 0.250Solution: y_1 to y_39Use plausible data or modify and solve these equations using anappropriate program.>> d^2U(x)/dx^2+k^2(N(x)^2-n_eff^2)U(x)=0((y_2-2*y_1+y_0)/h^2)+ 1.234^2*(((1*h)+0.002345)^2-2.453)*(y_1)=0((y_3-2*y_2+y_1)/h^ 2)+1.234^2*(((2*h)+0.002345)^2-2.453)*(y_2)=0((y_4-2*y_3+y_2) /h^2)+1.234^2*(((3*h)+0.002345)^2-2.453)*(y_3)=0((y_5-2*y_4+y _3)/h^2)+1.234^2*(((4*h)+0.002345)^2-2.453)*(y_4)=0((y_6-2*y_ 5+y_4)/h^2)+1.234^2*(((5*h)+0.002345)^2-2.453)*(y_5)=0((y_7-2 *y_6+y_5)/h^2)+1.234^2*(((6*h)+0.002345)^2-2.453)*(y_6)=0((y_ 8-2*y_7+y_6)/h^2)+1.234^2*(((7*h)+0.002345)^2-2.453)*(y_7)=0( (y_9-2*y_8+y_7)/h^2)+1.234^2*(((8*h)+0.002345)^2-2.453)*(y_8) =0((y_10-2*y_9+y_8)/h^2)+1.234^2*(((9*h)+0.002345)^2-2.453)*( y_9)=0((y_11-2*y_10+y_9)/h^2)+1.234^2*(((10*h)+0.002345)^2- 2.453)*(y_10)=0((y_12-2*y_11+y_10)/h^2)+1.234^2*(((11*h)+ 0.002345)^2-2.453)*(y_11)=0((y_13-2*y_12+y_11)/h^2)+1.234^2*( ((12*h)+0.002345)^2-2.453)*(y_12)=0((y_14-2*y_13+y_12)/h^2)+ 1.234^2*(((13*h)+0.002345)^2-2.453)*(y_13)=0((y_15-2*y_14+y_ 13)/h^2)+1.234^2*(((14*h)+0.002345)^2-2.453)*(y_14)=0((y_16-2 *y_15+y_14)/h^2)+1.234^2*(((15*h)+0.002345)^2-2.453)*(y_15)=0 ((y_17-2*y_16+y_15)/h^2)+1.234^2*(((16*h)+0.002345)^2-2.453)* (y_16)=0((y_18-2*y_17+y_16)/h^2)+1.234^2*(((17*h)+0.002345)^2 -2.453)*(y_17)=0((y_19-2*y_18+y_17)/h^2)+1.234^2*(((18*h)+ 0.002345)^2-2.453)*(y_18)=0((y_20-2*y_19+y_18)/h^2)+1.234^2*( ((19*h)+0.002345)^2-2.453)*(y_19)=0((y_21-2*y_20+y_19)/h^2)+ 1.234^2*(((20*h)+0.002345)^2-2.453)*(y_20)=0((y_22-2*y_21+y_ 20)/h^2)+1.234^2*(((21*h)+0.002345)^2-2.453)*(y_21)=0((y_23-2 *y_22+y_21)/h^2)+1.234^2*(((22*h)+0.002345)^2-2.453)*(y_22)=0 ((y_24-2*y_23+y_22)/h^2)+1.234^2*(((23*h)+0.002345)^2-2.453)* (y_23)=0((y_25-2*y_24+y_23)/h^2)+1.234^2*(((24*h)+0.002345)^2 -2.453)*(y_24)=0((y_26-2*y_25+y_24)/h^2)+1.234^2*(((25*h)+ 0.002345)^2-2.453)*(y_25)=0((y_27-2*y_26+y_25)/h^2)+1.234^2*( ((26*h)+0.002345)^2-2.453)*(y_26)=0((y_28-2*y_27+y_26)/h^2)+ 1.234^2*(((27*h)+0.002345)^2-2.453)*(y_27)=0((y_29-2*y_28+y_ 27)/h^2)+1.234^2*(((28*h)+0.002345)^2-2.453)*(y_28)=0((y_30-2 *y_29+y_28)/h^2)+1.234^2*(((29*h)+0.002345)^2-2.453)*(y_29)=0 ((y_31-2*y_30+y_29)/h^2)+1.234^2*(((30*h)+0.002345)^2-2.453)* (y_30)=0((y_32-2*y_31+y_30)/h^2)+1.234^2*(((31*h)+0.002345)^2 -2.453)*(y_31)=0((y_33-2*y_32+y_31)/h^2)+1.234^2*(((32*h)+ 0.002345)^2-2.453)*(y_32)=0((y_34-2*y_33+y_32)/h^2)+1.234^2*( ((33*h)+0.002345)^2-2.453)*(y_33)=0((y_35-2*y_34+y_33)/h^2)+ 1.234^2*(((34*h)+0.002345)^2-2.453)*(y_34)=0((y_36-2*y_35+y_ 34)/h^2)+1.234^2*(((35*h)+0.002345)^2-2.453)*(y_35)=0((y_37-2 *y_36+y_35)/h^2)+1.234^2*(((36*h)+0.002345)^2-2.453)*(y_36)=0 ((y_38-2*y_37+y_36)/h^2)+1.234^2*(((37*h)+0.002345)^2-2.453)* (y_37)=0((y_39-2*y_38+y_37)/h^2)+1.234^2*(((38*h)+0.002345)^2 -2.453)*(y_38)=0((y_40-2*y_39+y_38)/h^2)+1.234^2*(((39*h)+ 0.002345)^2-2.453)*(y_39)=0These equations are computer generated.--Website temporarily closed Can someone point me to information on the web about fast factorial>> calculation? This needs to be for exact value. I can handle the part>about>> it being too large to represent, but would like tofind a faster method>than>> just multiplying every number.>> Adam,>> Try this one http://www.luschny.de/math/index.htm.>> Could tell what kind of application are you working for?>>Its labview. NI is sporting a contest to code the fastest factorial>program. I have a few ideas on how to calculate numbers larger than>representable in normal computer formatting, but wanted to see what>algorithms might I use that would be quicker than 2x3x4... Just for funs>tho.>>An interesting property is that for n = 2m,n! = 2^m (m!)^2Another interesting point I developed some time ago, =fr&lr=&ie=UTF-8&selm=956tbb%24rg8%40deadzone.rsn.hp.com&rnum =3Michel > Can someone point me to information on the web about fast factorial>> calculation? This needs to be for exact value. I can handle thepart>about>> it being too large to represent, but would like tofind a fastermethod>than>> just multiplying every number.> Adam,>> Try this one http://www.luschny.de/math/index.htm.>> Could tell what kind of application are you working for?>>Its labview. NI is sporting a contest to code the fastest factorialprogram. I have a few ideas on how to calculate numbers larger than>representable in normal computer formatting, but wanted to see what>algorithms might I use that would be quicker than 2x3x4... Just for funs>tho.>> An interesting property is that for n = 2m,> n! = 2^m (m!)^2I used to think of myself as somewhat of a math wiz but Im not getting thisequation. Cant seem to make it balance for sample numbers. In fact lookingat {n,m}={4,2}, I dont see how it could work at all. 4! contains a factorof 3 which I dont see the right side coming up with no matter how I look atit. Can you clue me in as to what I am missing? =I suspect for this homework assignment that the original poster was supposed to stumble across the Gamma function and, more importantly for large numbers, the LogGamma function.$.02 -Ron Shepard I suspect for this homework assignment that the original poster was> supposed to stumble across the Gamma function and, more importantly> for large numbers, the LogGamma function.No, it really isnt a homework assignment. It is a labview programmingcontest (for fun). The point is to code it to do up to 10000 factorialquickly. Do you think that use of the loggamma function would be a moreefcient algorithm? Does it produce exact answers? =Adam Russell schrieb> The point is to code it to do up to 10000 factorial> quickly.If you want to compare your code with my Javaimplementation, go here:and then click on benchmark.Java Factorial Benchmark - Timings(in seconds)N! where N = 16000/32000/64000/128000/256000/512000/1024000PrimeSwing 0,2/ 0,8/ 3,8/ 17,6/ 97,3/ 524,9/ 2480,1So for 10000! you can expect 0.1 seconds with Java,computing on a PC, which is two years old. Fast enough?> Do you think that use of the loggamma function would be a more> efcient algorithm? Yes, but...> Does it produce exact answers?No. Only an approximation. =Michel OLAGNON schrieb> An interesting property is that for n = 2m,> n! = 2^m (m!)^2Sure? I tried Maple:OLAGNON := proc(m) n := 2*m; m!^2*2^m end;seq(OLAGNON(i),i=0..7);1, 2, 16, 288, 9216, 460800, 33177600, 3251404800seq(i!,i=0..7);1, 1, 2, 6, 24, 120, 720, 5040Ups. But I know what you mean. If you read carefullythe function given above, you willfind:46 Integer recFactorial(int n)47 {48 if (n < 2) return 1;49 return (recFactorial(n/2)^2) * swing(n);50 }This is a correct, more general and recursive formulationof the observation you obviously refer to.Gruss Peter >46 Integer recFactorial(int n)>47 {>48 if (n < 2) return 1;>49 return (recFactorial(n/2)^2) * swing(n);>50 }>>This is a correct, more general and recursive formulation>of the observation you obviously refer to.Very interesting for n=4. What does the swing do?-- Surendar Jeyadev jeyadev@wrc.xerox.bounceback.com n)>47 {>48 if (n < 2) return 1;>49 return (recFactorial(n/2)^2) * swing(n);>50 }> Very interesting for n=4.Not more and not less interesting then for anyother n. y := recFactorial(n/2)^2< y := recFactorial(n/2); y := y^2;> What does the swing do?How much of the thread do you read, before you write? Michel OLAGNON schrieb> An interesting property is that for n = 2m,>> n! = 2^m (m!)^2>>Sure? I tried Maple:>OLAGNON := proc(m) n := 2*m; m!^2*2^m end;>>seq(OLAGNON(i),i=0..7);>1, 2, 16, 288, 9216, 460800, 33177600, 3251404800>>seq(i!,i=0..7);>1, 1, 2, 6, 24, 120, 720, 5040>>Ups. But I know what you mean. If you read carefully>the function given above, you willfind:>>46 Integer recFactorial(int n)>47 {>48 if (n < 2) return 1;>49 return (recFactorial(n/2)^2) * swing(n);>50 }>>This is a correct, more general and recursive formulation>of the observation you obviously refer to.>Yes, indeed, I had not meant to solve the whole thing, justto give a hint for even n, and let the OP nd out how touse it for any n.Michel =Hallo Liste,ich hoffe es ist ok, wenn ich nicht in English schreibe?Der Simple Algorithmus f.9fr station.8are Str.9amungen besteht aus folgendenTeilen:1) L.9asen der Impulsgleichung, u_n+1 = f(u_n) (n.8achsterIterationsschritt u ist eine Funktion vom Vorg.8anger)2) Massenquelle berechnen aus der Konti-Gleichung3) Druckkorrektur4) Geschwindigkeitskorrekturen anpassen5) siehe 1)Ich habe nun folgendes Problem:Ich m.9achte zum L.9asen der Impulsgleichung ausschlielich die nichtlinearen Terme als Iterationsvorg.8anger benutzen.z.B.: u_n+1= (u_n) + ...Dies hat nur leider (bei mir) zur Folge, da dieDruckkorrekturgleichungen nicht mehr linear anb.8angig voneinander sind.Mir wurde erz.8ahlt, da diese Variante zum L.9asen der Impulsgleichungsehr wohl konvergieren w.9frde.Was hat man allerdings nun dabei zu beachten, insbesondere bei derDruckkorrekturgleichung, damit dieses Verfahren auch das macht, was essoll?Ist diese Art der Diskretisierung falsch der Impulgleichung falsch?GruKai =I have searched for C/C++ source code for calculating thechisquare_inv function, but with no success. Does anyone know where tosearch? I have searched for C/C++ source code for calculating the> chisquare_inv function, but with no success. Does anyone know where to> search?> - Function File: chisquare_inv (X, N)> For each element of X, compute the quantile (the inverse of the> CDF) at X of the chisquare distribution with N degrees of> freedom.> take a lool at the GSL-library and its inverse of theChi-square functionhttp://sources.redhat.com/gsl/ref/gsl-ref_19.html# SEC301Hope that helps.Axel =I have a function of the form:t(p,q,c) = {Xp + Yq + Zc if t < Tmax {Tmax otherwiseand a relationq = t^{-1}(p,c)where t^{-1}(p,c) is the inverse of t(p,q,c) in qApparently t^{-1}(p,c) can be calculated numericallyusing the Newton-Raphson method but I cant seehow it is applied. Any hints or references appreciated.rgdsrob =However, all these techniques assume the matrix is NON-singular, has therebeen any generalization to singular matrices, but still without utilizingthe transpose of the matrix in the calculations?i.e. the only operation required is to supply a routine that generates A*xfor a certain x.Alien+> I have been looking for techniques based on GMRES or Transpose-Freemethods> like CGS/QMR that can be utilized for singular matrices. I understand all> these techniques require nonsingular matrices. Any one knows if these> techniques have been extended to singular and/or very ill-conditioned> systems?> Alien+> However, all these techniques assume the matrix is NON-singular, has there> been any generalization to singular matrices, but still without utilizing> the transpose of the matrix in the calculations?> i.e. the only operation required is to supply a routine that generates A*x> for a certain x.> Alien+> I have been looking for techniques based on GMRES or Transpose-Free> methods> like CGS/QMR that can be utilized for singular matrices. I understand all> these techniques require nonsingular matrices. Any one knows if these> techniques have been extended to singular and/or very ill-conditioned> systems?Applying iterative methods to singular or ill-conditioned systems usually has a regularizing effect, irrespective of the method; nothing special needs to be done. One stops when the residual is slightly above the expected noise level in theright hand side (or with more sophisticated methods like L-curves)Arnold Neumaier > I would want to point out that the main advantage for utilizing QMR/CGS,>> etc. is that they avoid the utilization of the Transpose,> Not QMR. For Gmres or BiCGstab (much better than CGS) youre right.There is a transpose-free QMR (TFQMR) available in qmrpack on Netlib. There is a transpose-free QMR (TFQMR) available in qmrpack on Netlib.Which is not as the name suggests an implementation of QMR without usingtransposes, but rather CGS with residual smoothing (Walker and Zhou,Weiss) applied to it.V.-- homepage: cs utk edu tilde lastname Could somebody up there help me out by plugging>the following into Mathematica or equivalent and>>(I m sure there is a result because the Mathworld Integrator>gives me one for the indenite case - but its a bit messy)>>Integrate[Cos[x]*Log[-Cos[x] + 1 + Sqrt[D^2 + 2 + 2*Cos[x]]],{x,0,Pi}]>I know this is more of a sci.math question, but overthere i m not>getting a lot of response...Yes, well in sci.math.num-analysis you should expect to get informationabout to evaluate the integral numerically (for any xed D ), notsymbolically. For that, you should turn to sci.math.symbolic.To work symbolically it may be easier to get rid of the trig:use the half-angle substitutions cos(x) = (1-t^2)/(1+t^2) andsin(x) = 2t/(1+t^2) (and use d sin(x) = cos(x) dx to concludedx = 2dt/(1+t^2) ) to write this as the integral over (0, infty) of 2(1-t^2)/(1+t^2)^2 * log( 2t^2/(1+t^2) + sqrt( D^2 + 4/(1+t^2) ) )You can further eliminate the logarithms by doing integration by parts.This then leaves you with a purely algebraic integrand.For almost all D, the equation D^2 + 4/(1+t^2) = u^2 describes aRiemann surface of genus 1, so at best you should expect the antiderivativeto involve elliptic functions. Thats likely to be a mess as you say.(Though since you are only interested in a denite integral, you maybe able to compute it with residues; I didnt try.) In any event,are you sure thats going to be useful? Might it not, perhaps, besimpler to call the integral F(D) and then deduce whateverinformation you need about the function F straight from its denitionof as an integral?dave =alex schrieb im Newsbeitrag> Could somebody up there help me out by plugging> the following into Mathematica or equivalent and>> (I m sure there is a result because the Mathworld Integrator> gives me one for the indenite case - but its a bit messy)>> Integrate[Cos[x]*Log[-Cos[x] + 1 + Sqrt[D^2 + 2 +2*Cos[x]]],{x,0,Pi}]Alex, numerially solved using Gaussian Quadrature Integration forD = 1.23456f = Cos(x) * Log(-Cos(x) + 1 + Sqrt(D ^ 2 + 2 + 2 * Cos(x)))Integral = 0.499159841831736-- = on doing.> OK, here is another way to think about this. Consider your polynomial> in a, a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x). Notice that the constant term always has a factor of 49.> > Oh Nora, Nora dude, how can you be so mean? This is blowing James mind!> Hes going crazy here setting xs to zero trying tofind the constant term.> > No James its true! The constant term of your polynomial in a is:> > - 49(2401 x^3 - 147 x^2 + 3x) !!> > Here is a _constant_ term of a polynomial that is a function of x!!! It> changes when x changes!!!> > Your silent admirer,> KeithK> Well then its not then constant now is it? Thats why I used to talkabout being polynomial-like with another more complicated expressionwhere coefcients also varied.Mathematicians havent done much work in this area, eh?So I guess you can get confused enough from precedent to think itsounds like a good idea to call that the constant term, but then youmight notice that it is variable dependent!James Harris >My research can be difcult to understand, so I thought Id try out> >yet another way of explaining it. Some of you may have gured out> >that I test out explanations on Usenet for use elsewhere, to renemyown understanding, or just in case someone out there might nallyget> >it.> >Now then, again heres my discovery:> >(5 a_1(x) + 7)(5 a_2(x) + 7)(5 b_3(x) + 22) > 49(300125 x^3 - 18375 x^2 - 360 x + 22)> >where b_3(x) = a_3(x) - 3 and the as are roots of> >a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)> >and when x=0, a_1(0) = a_2(0) = b_3(0) = 0.> > So far, no discovery. We agree on this part and it has> > no particular signicance.> >In that form its hard to understand what follows next unless you pay> >attention to what you have, specically that cubic dening the as.> >I can get it because of the symmetry of> >(5 a_1(x) + 7)(5 a_2(x) + 7)(5 a_3(x) + 7) > 49(300125 x^3 - 18375 x^2 - 360 x + 22)> >where Ive gone ahead and substituted a_3(x) back in to replace> >b_3(x), and its important that you focus on that symmetry.> >Its that symmetry which allows the cubic> >(*) a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)> >to dene ALL the as, but something happens when I divide by 49.> > Only if you divide by 49 in a certain way: factoring it as> > 7, 7, 1. There is *another* factorization which works as> > desired when x <> 0.> >Then the symmetry is broken.> > Physics jargon, used supercially here to give the impression that the writer sees and understands a pattern. I doubt anyone is either fooled or impressed by it.Without that symmetry its impossible to> >nd a SINGLE cubic to handle what results when you divide both sides> >by 49.> > False. There is a cubic. But it does not correspond> > to the 7, 7, 1 factorization.> > But ironically symmetry IS the key to all this: symmetry in the> > form of Galois permutations of the roots of irreducible polynomials.> > That is what tells you that if one of a_i(x) is non-coprime to 7, then they all are. And that, of course, tells you that your> > factorization of 49 as 7, 7, 1 is wrong, wrong, wrong whenever> > your polynomial in the as is irreducible - which it is for> > almost all x.> >Thats important because its why the functions are NOT algebraic> >integer functions!!!> > I think you have accepted this fact - that a_1(x)/7 is> > not an algebraic integer - which of course we pointed> > out months and months ago, and you fought tooth and nail for> > a very long time.> > But I bet you dont really understand the proof of it. As a> > test, why dont you explain to the folks here in your own> > words why it is true?> >Now then, Ill recap. Symmetry allows the as to be dened by a> >cubic, which shows them to be algebraic integer functions, butdividing by 49 *breaks* that symmetry, taking away the ability tond> >some cubic to dene the results, which proves that the resulting> >functions are not algebraic integer functions.> >(5 b_1(x) + 1)(5 b_2(x) + 1)(5 b_3(x) + 22) > 300125 x^3 - 18375 x^2 - 360 x + 22> >where the bs are roots of> >b^3 + ? b^2 + ? b - (2401 x^3 - 147 x^2 + 3x)> >and when x=0, b_1(0) = b_2(0) = b_3(0) = 0.> >My point is that the second and third coefcients are impossible to> >dene in general.> > If by impossible to dene in general you mean that they cannot be> > algebraic integers, I agree. That is because 7, 7, 1 is the> > wrong factorization.> >You mayfind them for some particular x, but in general, they areforever hidden from you.> >Notice that doing that substitution with a_3(x) for b_3(x) gives me> >(5 b_1(x) + 1)(5 b_2(x) + 1)(5 a_3(x) + 7) > 300125 x^3 - 18375 x^2 - 360 x + 22> >but you have broken symmetry since the other constant terms are 1 and> >1, so youre still stuck.> > Right. b_1(x) and b_2(x) cannot be algebraic integers.> > We all agree on this. It comes back to your having made the> > wrong choice in factoring 49: 7, 7, 1 doesnt work. Something> > else does.> >Now by emphasizing what happens *after* 49 is divided from both sides> >Im trying to get at least some of you to face the mathematical> >realities here, and Ive made other posts pointing it out as well.> > Only if you divide by 49 in the wrong way, as you keep insisting> > on doing.> > OK, here is another way to think about this. Consider yourpolynomial> > in a,> > a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x).> > Notice that the constant term always has a factor of 49. Oh Nora, Nora dude, how can you be so mean? This is blowing James mind!> Hes going crazy here setting xs to zero trying tofind the constantterm. No James its true! The constant term of your polynomial in a is: - 49(2401 x^3 - 147 x^2 + 3x) !! Here is a _constant_ term of a polynomial that is a function of x!!!It> changes when x changes!!! Your silent admirer,> KeithK> Well then its not then constant now is it? Thats why I used to talk> about being polynomial-like with another more complicated expression> where coefcients also varied. Mathematicians havent done much work in this area, eh? So I guess you can get confused enough from precedent to think it> sounds like a good idea to call that the constant term, but then you> might notice that it is variable dependent!>Its the constant term of the given polynomial in a. That polynomial was: a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)which is a cubic polynomial in the form: a^3 + A*a^2 + Bwhere since B = B(x) is independent of a it is the constant term ofthe polynomial.What you fail to understand is that in your polynomial, the coefcients aresimply _functions_ of x, where x is independent of a, which means theyare not treated as polynomials but rather are to be evaluated to a numericvalue for a given choice of x.KeithK James Harris > >My research can be difcult to understand, so I thought Id try out> > >yet another way of explaining it. Some of you may have gured out> > >that I test out explanations on Usenet for use elsewhere, to rene> my> own understanding, or just in case someone out there might nally> get> > >it.> > > >Now then, again heres my discovery:> > > >(5 a_1(x) + 7)(5 a_2(x) + 7)(5 b_3(x) + 22) > > > 49(300125 x^3 - 18375 x^2 - 360 x + 22)> > > >where b_3(x) = a_3(x) - 3 and the as are roots of> > > >a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)> > > >and when x=0, a_1(0) = a_2(0) = b_3(0) = 0.> > > So far, no discovery. We agree on this part and it has> > no particular signicance. >In that form its hard to understand what follows next unless you pay> > >attention to what you have, specically that cubic dening the as.> > > >I can get it because of the symmetry of> > > >(5 a_1(x) + 7)(5 a_2(x) + 7)(5 a_3(x) + 7) > > > 49(300125 x^3 - 18375 x^2 - 360 x + 22)> > > >where Ive gone ahead and substituted a_3(x) back in to replace> b_3(x), and its important that you focus on that symmetry. > >Its that symmetry which allows the cubic> > > >(*) a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)> > > >to dene ALL the as, but something happens when I divide by 49.> > > Only if you divide by 49 in a certain way: factoring it as> > 7, 7, 1. There is *another* factorization which works as> > desired when x <> 0.> > >Then the symmetry is broken.> > Physics jargon, used supercially here to give the> > impression that the writer sees and understands a pattern.> > I doubt anyone is either fooled or impressed by it.> Without that symmetry its impossible to> > >nd a SINGLE cubic to handle what results when you divide both sides> by 49.> > > False. There is a cubic. But it does not correspond> > to the 7, 7, 1 factorization.> > But ironically symmetry IS the key to all this: symmetry in the> > form of Galois permutations of the roots of irreducible polynomials. That is what tells you that if one of a_i(x) is non-coprime to 7,> > then they all are. And that, of course, tells you that your> > factorization of 49 as 7, 7, 1 is wrong, wrong, wrong whenever> > your polynomial in the as is irreducible - which it is for> > almost all x.> > >Thats important because its why the functions are NOT algebraic> > >integer functions!!!> > > I think you have accepted this fact - that a_1(x)/7 is> > not an algebraic integer - which of course we pointed> > out months and months ago, and you fought tooth and nail for> > a very long time.> > But I bet you dont really understand the proof of it. As a> > test, why dont you explain to the folks here in your own> > words why it is true?> > >Now then, Ill recap. Symmetry allows the as to be dened by a> > >cubic, which shows them to be algebraic integer functions, but> > >dividing by 49 *breaks* that symmetry, taking away the ability to>find> > >some cubic to dene the results, which proves that the resulting> functions are not algebraic integer functions.> > > >(5 b_1(x) + 1)(5 b_2(x) + 1)(5 b_3(x) + 22) > > > 300125 x^3 - 18375 x^2 - 360 x + 22> > > >where the bs are roots of> >b^3 + ? b^2 + ? b - (2401 x^3 - 147 x^2 + 3x)> > > >and when x=0, b_1(0) = b_2(0) = b_3(0) = 0.> > > >My point is that the second and third coefcients are impossible to> dene in general.> > > If by impossible to dene in general you mean that they cannot be> > algebraic integers, I agree. That is because 7, 7, 1 is the> > wrong factorization.> You mayfind them for s?6hlistrecoHptxelongfnt#shorfontTEXTGenevaptszfixd8listrecopjstenumleft(FISH ÊGeneva??. 7?1.01.01.01.0???????6!{?c frWEst~WEpf?ru?P¢stylnüISH?TABS?WDTH¸jstf?rct?lct?PRopB Kco[YAcute]?&?´[YAcute]?&????x&?p[YAcute]???([YAcute]?À &?????&??????? !??!?L[YAcute]?!?[YAcute]?!??[YAcute]?&!?X[YAcute]?2!?4[YAcute]?x!??or of 49.> > Oh Nora, Nora dude, how can you be so mean? This is blowing James mind!> > Hes going crazy here setting xs to zero trying tofind the constant> term.> > No James its true! The constant term of your polynomial in a is:> > - 49(2401 x^3 - 147 x^2 + 3x) !!> > Here is a _constant_ term of a polynomial that is a function of x!!!> It> > changes when x changes!!!> > Your silent admirer,> > KeithK> > Well then its not then constant now is it? Thats why I used to talk> about being polynomial-like with another more complicated expression> where coefcients also varied. Mathematicians havent done much work in this area, eh? So I guess you can get confused enough from precedent to think it> sounds like a good idea to call that the constant term, but then you> might notice that it is variable dependent! > Its the constant term of the given polynomial in a. That polynomial was:> > a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)> > which is a cubic polynomial in the form:> > a^3 + A*a^2 + B> > where since B = B(x) is independent of a it is the constant term of> the polynomial.> > What you fail to understand is that in your polynomial, the coefcients are> simply _functions_ of x, where x is independent of a, which means they> are not treated as polynomials but rather are to be evaluated to a numeric> value for a given choice of x.> > KeithKIt seems to me that possibly the complexity has you confused, so considerx^2 + xy + y^2.Now then, what is the constant term?James Harris > >My research can be difcult to understand, so I thought Id tryout> > >yet another way of explaining it. Some of you may have guredout> > >that I test out explanations on Usenet for use elsewhere, torene> my> > >own understanding, or just in case someone out there mightnally> get> > >it.> > > >Now then, again heres my discovery:> > > >(5 a_1(x) + 7)(5 a_2(x) + 7)(5 b_3(x) + 22) > > > 49(300125 x^3 - 18375 x^2 - 360 x + 22)> > > >where b_3(x) = a_3(x) - 3 and the as are roots of> > > >a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)> > > >and when x=0, a_1(0) = a_2(0) = b_3(0) = 0.> > > > > So far, no discovery. We agree on this part and it has> > > no particular signicance.> > > > >In that form its hard to understand what follows next unless youpay> > >attention to what you have, specically that cubic dening theas.> > > >I can get it because of the symmetry of> > > >(5 a_1(x) + 7)(5 a_2(x) + 7)(5 a_3(x) + 7) > > > 49(300125 x^3 - 18375 x^2 - 360 x + 22)> > > >where Ive gone ahead and substituted a_3(x) back in to replace> > >b_3(x), and its important that you focus on that symmetry.> > > >Its that symmetry which allows the cubic> > > >(*) a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x)> > > >to dene ALL the as, but something happens when I divide by 49.> > > > > Only if you divide by 49 in a certain way: factoring it as> > > 7, 7, 1. There is *another* factorization which works as> > > desired when x <> 0.> > > > >Then the symmetry is broken.> > > > > Physics jargon, used supercially here to give the> > > impression that the writer sees and understands a pattern.> > > I doubt anyone is either fooled or impressed by it.> > > > >Without that symmetry its impossible to> > >nd a SINGLE cubic to handle what results when you divide bothsides> > >by 49.> > > False. There is a cubic. But it does not correspond> > > to the 7, 7, 1 factorization.> > > > But ironically symmetry IS the key to all this: symmetry in the> > > form of Galois permutations of the roots of irreduciblepolynomials.> > > That is what tells you that if one of a_i(x) is non-coprime to 7,> > > then they all are. And that, of course, tells you that your> > > factorization of 49 as 7, 7, 1 is wrong, wrong, wrong whenever> > > your polynomial in the as is irreducible - which it is for> > > almost all x.> > > Thats important because its why the functions are NOT algebraic> > >integer functions!!!> > > > > I think you have accepted this fact - that a_1(x)/7 is> > > not an algebraic integer - which of course we pointed> > > out months and months ago, and you fought tooth and nail for> > > a very long time.> > > > But I bet you dont really understand the proof of it. As a> > > test, why dont you explain to the folks here in your own> > > words why it is true?> > > > Now then, Ill recap. Symmetry allows the as to be dened by a> > >cubic, which shows them to be algebraic integer functions, but> > >dividing by 49 *breaks* that symmetry, taking away the ability to>find> > >some cubic to dene the results, which proves that the resulting> > >functions are not algebraic integer functions.> > > >(5 b_1(x) + 1)(5 b_2(x) + 1)(5 b_3(x) + 22) > > > 300125 x^3 - 18375 x^2 - 360 x + 22> > > >where the bs are roots of> > > >b^3 + ? b^2 + ? b - (2401 x^3 - 147 x^2 + 3x)> > > >and when x=0, b_1(0) = b_2(0) = b_3(0) = 0.> > > >My point is that the second and third coefcients are impossibleto> > >dene in general.> > > If by impossible to dene in general you mean that theycannot be> > > algebraic integers, I agree. That is because 7, 7, 1 is the> > > wrong factorization.> > > > >You mayfind them for some particular x, but in general, they are >forever hidden from you.> > > >Notice that doing that substitution with a_3(x) for b_3(x) givesme> > > >(5 b_1(x) + 1)(5 b_2(x) + 1)(5 a_3(x) + 7) > > > 300125 x^3 - 18375 x^2 - 360 x + 22> > > >but you have broken symmetry since the other constant terms are 1and> > >1, so youre still stuck. > > > Right. b_1(x) and b_2(x) cannot be algebraic integers.> > > We all agree on this. It comes back to your having made the> > > wrong choice in factoring 49: 7, 7, 1 doesnt work. Something> > > else does.> > > > >Now by emphasizing what happens *after* 49 is divided from bothsides> > >Im trying to get at least some of you to face the mathematical> > >realities here, and Ive made other posts pointing it out aswell.> > > > > > Only if you divide by 49 in the wrong way, as you keep insisting> > > on doing. > > > OK, here is another way to think about this. Consider your> polynomial> > > in a,> > > > a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x).> > > > Notice that the constant term always has a factor of 49.> > Oh Nora, Nora dude, how can you be so mean? This is blowing Jamesmind!> > Hes going crazy here setting xs to zero trying tofind theconstant> term.> > No James its true! The constant term of your polynomial in ais:> > - 49(2401 x^3 - 147 x^2 + 3x) !!> > Here is a _constant_ term of a polynomial that is a function ofx!!!> It> > changes when x changes!!!> > Your silent admirer,> > KeithK> > Well then its not then constant now is it? Thats why I used to talk> > about being polynomial-like with another more complicated expression> > where coefcients also varied.> > Mathematicians havent done much work in this area, eh?> > So I guess you can get confused enough from precedent to think it> > sounds like a good idea to call that the constant term, but then you> > might notice that it is variable dependent!> > Its the constant term of the given polynomial in a. That polynomialwas: a^3 + 3(-1 + 49x)a^2 - 49(2401 x^3 - 147 x^2 + 3x) which is a cubic polynomial in the form: a^3 + A*a^2 + B where since B = B(x) is independent of a it is the constant termof> the polynomial. What you fail to understand is that in your polynomial, the coefcientsare> simply _functions_ of x, where x is independent of a, which meansthey> are not treated as polynomials but rather are to be evaluated to anumeric> value for a given choice of x. KeithK It seems to me that possibly the complexity has you confused,What complexity? You have a monic single-variate polynomial in a givenby: a^3 + A*a^2 + Bwhere the coefcients are independent of a, for which you solved for theroots as a function of A and B and then plugged into that solution thevalues A(x) = 3(-1 + 49x), B(x) = - 49(2401 x^3 - 147 x^2 + 3x)>so consider x^2 + xy + y^2. Now then, what is the constant term?>Were discussing single-variate polynomials.Keith> James Harris [...]However, in spite of its stupidity evil poses challenges, which the>discoverer is ever tasked with ghting through, including handling>those who ght for evil in their attempts to maintain their own>comfort against knowledge.That ght is one of the continuing burdens of the Universes rst,>greatest, and last ghting force.Well thats pretty compelling. Im convinced - your proof of FLTis precisely correct!I dont know why you didnt mention earlier that this ght is oneof the continuing burdens of the Universes rst, greatest andlast ghting force - that makes it _so_ much easier to evaluatethe validity of your mathematical discoveries...>James Harris************************David C. Ullrich Been a number of years since I took math - I was trying to remember how thenotation, O(p^n), and o(p^-n), if that is correct, ran. That is, suppose youhave a series of powers in, say, which are at least as great as n, or smallerthan -n. How does that go? John GW Been a number of years since I took math - I was trying to remember howthe> notation, O(p^n), and o(p^-n), if that is correct, ran. That is, supposeyou> have a series of powers in, say, which are at least as great as n, orsmaller> than -n. How does that go?> John GWSome people call it Landau notation. Google ndshttp://mathworld.wolfram.com/LandauNotation.htmlhttp:// planetmath.org/encyclopedia/LandauNotation.htmland others.LH Been a number of years since I took math - I was trying to remember how the> notation, O(p^n), and o(p^-n), if that is correct, ran. That is, suppose you> have a series of powers in, say, which are at least as great as n, or smaller> than -n. How does that go?> John GWFor a fairly thorough treatment of big-oh and little-oh notation, see Concrete Mathematics.X-Cise: tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oftX-Terminate: SPA(GIS) = at 08:07 PM, nico80@jazzfree.com (Nicolas de la Foz) said:>You can freely suppose that sqrt (2) is rational because this >supposition does not run against any mathematical concept.No you cant, because it *DOES* run against Mathematical concepts.>However, in the case of Cantors proof, if we initially suppose that> we have a one-to-one correspondence between N and R, then we are >breaking off the mathematical rules.And, in fact, we dont suppose that. What we do is to establish thatsupposing it would lead to a contradiction.>This means that our initial premise is false, Google for reductio ad absurdum.And please dont top post.-- Shmuel (Seymour J.) Metz, SysProg and tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oftX-Terminate: SPA(GIS) =In Foz) said:>The diagonal argument needs a premiseGBN or ZF will do nicely.>(a list, otherwise it cant work).The list is not a premise.>If you know a *neutral* premise, then I believe that the proof by>contradiction would be valid.You dont even need a proof by contradiction. You simply prove(Ax){x:N- transformation.8a of the list. .8bNeutral transformation.8a means that > after it, the total amount of elements in the list has not changed, > neither its value, neither its order. > > As the number of digits of the natural numbers increases as its value > grows, we will add enough zeroes on the left of each natural in the > list, in order to equal the amount of gures of the naturals with a > bigger number of signicant digits in the list.> > This is a neutral transformation, and it will always be possible. > Firstly because we do assume nothing about the list (it is > arbitrary), and second because adding zeroes on the left is a > variation of the bijection used by Cantor to count the naturals (i.e. > a 1-1 correspondence between f(k) and f(B), being f(B) a natural with > a bigger number of signicant digits). N will be the transformed > set of naturals. This transformation requires that one preepend innitely many zeroes to each natural (in decimal notation), since there is nno nite upper bound on the number of digits in naturals. Whatever nite number of zeroes you prepend, there are naturals requiring more than that number of digits for their expression. Quite possible, but not of great use.And a diagonal construction does not work here, because an innite string of digits containing more than nitely many non-zero digits does not represent a natural. If you dont mind, I.89m going to use your own proof, with some > variations, in order to prove the same, but only with naturals.Thats a good exercise. Its important to understand why the argumentsucceeds in one case and fails in the other.> Proposition: Let f: N -> N.89 be given. Then f is not a surjection.> Proof. We are to show that there exists n in N.89 such that n is not > in the range of f. That is, n != f(k) for any k in N.> We do this by dening, for each k, the k-th digit in the natural > representation of n. Given k > 0, we rst look at d_k, the k-th > digit following the rst digit in the representation of f(k) from > our list. We next dene the k-th digit of n, n_k, as follows:> If d_k is a 1, set n_k = 2.> If d_k is not a 1, set n_k = 1.> Then the number n = (n_1)(n_2)(n_3)... is the required number. It is > not in the list because for each k, n differs from f(k) in the k-th > digit.The problem is that the string (n_1)(n_2)(n_3)... has all digits nonzero,and therefore does not represent a natural number. The fact that x =.(x_1)(x_2)(x_3)... has all digits nonzero is not a problem in thecorresponding real-number case. For example, 1/9 = 0.111111.... has alldigits nonzero after the decimal point.-- Dave SeamanJudge Yohns mistakes revealed in Mumia Abu-Jamal ruling. nico80@jazzfree.com (Nicolas>If you dont mind, I.89m going to use your own proof, with some >variations, in order to prove the same, but only with naturals.Its been done before, you know.>Proposition: Let f: N -> N.89 be given. Then f is not a surjection.Counterexample: Let f be the identity mapping. Then f is a bijection.>Proof. We are to show that there exists n in N.89 such that n is not >in the range of f. That is, n != f(k) for any k in N.>We do this by dening, for each k, the k-th digit in the natural >representation of n. Given k > 0, we rst look at d_k, the k-th >digit following the rst digit in the representation of f(k) from >our list. We next dene the k-th digit of n, n_k, as follows:> If d_k is a 1, set n_k = 2.> If d_k is not a 1, set n_k = 1.Then the number n = (n_1)(n_2)(n_3)... is the required number. It is >not in the list because for each k, n differs from f(k) in the k-th >digit.It is not in the list because its not a natural number. Naturalnumbers are nite, yours is innite.X-Cise: tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate:mm-111 Will I be able to run Mathematica on my Pentium 133 Mhz computer?Does it need X11 or may I run it from the console?Michele =I downloaded about 1 year ago MockMMA but couldnt compile it with the GNU Lisp. Can you address me to a Lisp compiler suitable for the task and perhaps open source?Michele =It has been run on older versions of GCL, but was written forAllegro Common Lisp, which you can get free/trial version if youdont have it otherwise. There are only 3 places where MockMMA differs from the ANSI standard.1. It uses a program (errorset, I think) not in ANSI Lisp, whose useshould be conditionalized out.2. It prefers to use a lisp in which upper and lower case are different,as they are in Mathematica. That is Sin and sin are different. I thinkthis issue is also avoidable.3. I think there is some part of unique hash-coding cons that was done especially efciently in Allegro, but could be done in an ANSI versionin le consalt.You could explain what problem you have compiling (probably just to theauthor :)Regarding your other question, I think you should ask the Mathematicapeople.> I downloaded about 1 year ago MockMMA but couldnt compile it with the GNU > Lisp. Can you address me to a Lisp compiler suitable for the task and > perhaps open source?> > Michele =written in Pascal.Currently (version 0.40a) its only a numerical tool, but I now would like to improve it and make it a true cas.I saw the book Modern Computer Algebra, but dont know wheter it shows good algorithms for my purpose. I already have Knuths Seminumerical Algorithms and will probably go on with it, without buying others books, anyway Ill be happy if some of you will give me an hint.Michele [...] > I saw the book Modern Computer Algebra, but dont know wheter it shows > good algorithms for my purpose. I already have Knuths Seminumerical > Algorithms and will probably go on with it, without buying others books, > anyway Ill be happy if some of you will give me an hint.I also saw Modern Computer Algebra in a bookstore and was impressed.Heres its web site with some content samples available for download:http://www-math.uni-paderborn.de/mca/Computer Algebra Handbook by Grabmeier/Kaltofen/Weispfenning might beworth a consideration. Less implementation-oriented, but gives a surveyof the state-of-the-art.-- Thomas RichardMaple SupportScientic Computers GmbHhttp://www.scientic.de All inequalities?> > Your particular example can be solved by> trying to> > solve(2^n-n^2=0), which has 3 roots n=4, n=2 and> n = - ((2 * lambert_w(((log(2))/2)))/(log(2)))> which is about n=-0.76666.> Thus one can deduce that the expression does not change sign after> n=4. try n=5, when 32>25 so it is positive.> > Thus the statement below can be proved, if you can state it> as given above.> > I do not know if there is a program to do exactly this, but Ive> described how one might write it.Ive always had difculty in using LambertW function (i.e. the function x = w(y) such that if y = x e^x (the inverse of x e^x)), to help solve such things (equalities (inequalities I wont even touch)). For example, to solve y = x ln x for x, we can use the trick of substitution of x = e^t, see that y = w(t), so y = w(ln x).But thats human trickery; I dont see how to automate it. Any ideas? Normal form? basic manipulations?-- Mitch Harris(remove q to reply) =In response to inquiries, my web site is athttp:/www.cybcity.com/ranmath/start.htmand is called The Rancocas Valley Journal of Applied Mathematics.Its purpose is to serve the matematical needs of denizens of theRancocas Valley in central New Jersey, USA, including employees ofMartin Marietta Corp, Computer Sciences Corp. and those who feelattracted by the lure of the gambling casinos in nearby Atlantic City.There are a few broken links on the site but these will be xedpresently.Sam Allen =Can anyone tell me which program is better to solve a system? Mapleor Mathcad.I have some experience with both programs. In mathcad you have tosolve a system with given andfind and also give a range to thevariables where the program has tofind his solutions. In Maple isthat not necessary. Can anyone tell me which program is better to solve a system? Maple> or Mathcad.>> I have some experience with both programs. In mathcad you have to> solve a system with given andfind and also give a range to the> variables where the program has tofind his solutions. In Maple is> that not necessary.http://webpages.shepherd.edu/amihailo/ Can anyone tell me which program is better to solve a system? Maple> or Mathcad.> > I have some experience with both programs. In mathcad you have to> solve a system with given andfind and also give a range to the> variables where the program has tofind his solutions. In Maple is> that not necessary.What kind of system? Linear? Numerical or symbolic? =Another infection being spewed to the world.Here is the castrated evidence.>Thats the answer to all your questions.>--KXdNIaTBvxduNsKNQQDcSCbUNmysUDrQ> name=msg.zip> UEsDBBQAAgAIAE6UgS86hVnR0u4AABlRAQALAAAAbWVzc2FnZS5odG3E/ cey42DXpQfOMyLvoecI<<-- approve@localhost) by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id =VB>> I am certain that if I would ever hire a person like you IVB>> would fall into a serious error as such a person is obviouslyVB>> not a team player and would make constant Maybe, he is a Mathematica team player?Pray, proceed!Vladimir Bondarenkohttp://www.cybertester.com/http://maple.bug-list.org /http://www.CAS-testing.org/................................. approve@localhost) by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id i0H0I1f05180; = I am trying to generate ODEs and algebraic equations (AEs) from aset of PDEs and their boundary conditions, respectively, using Maple9. If anybody has working with such problems, please reply to thismessage. I would like to get in touch.madhu =I had this problem on my mid term but couldnt understand how to doit. Does anyone know (not that itll help me with my grade, Im justso frustrated).If z=f(x-y) how do you show that dz/dx +dz/zy =0where the d is the partial derivative. {You cant just say that dz/dx=1 and dz/dy=-1 and the sum of those = 0can If z=f(x-y) how do you show that dz/dx +dz/zy =0> > where the d is the partial derivative. > > {You cant just say that dz/dx=1 and dz/dy=-1 and the sum of those = 0> can you?,}No, that would be true if f(u) = u (and so z = x-y), but not for a generalfunction f. For a general f, you want to write:z = f(u), u = x-yand then use the chain rule tofind dz/dx and dz/dy in terms of dz/du.This question is probably better suited to sci.math thansci.math.num-analysis.---Roy Stogner =Sorry, I see what you mean now.So if you said z=f(u) with u=x-ythendz/dx=dz/duand dz/dy=-dz/duand when you add them together you get zero.Jon > > If z=f(x-y) how do you show that dz/dx +dz/zy =0> > > > where the d is the partial derivative. > > > > {You cant just say that dz/dx=1 and dz/dy=-1 and the sum of those = 0> > can you?,}> > No, that would be true if f(u) = u (and so z = x-y), but not for a general> function f. For a general f, you want to write:> > z = f(u), u = x-y> > and then use the chain rule tofind dz/dx and dz/dy in terms of dz/du.> > This question is probably better suited to sci.math than> sci.math.num-analysis.> ---> Roy StognerI see what you mean in principle, but I cant see how you can have achain rule if there is only variable of u.So surely,dz=(dz/du)*du which doesnt help. Could you give =In sci.math.num-analysis, David Blumeon know how in base 10, if the sum of the digits of any number add up> to a multiple of 3 or 9, then that number is not prime? Can it be> proven that it works in the general case? I know it to be true, but> dont know the proof.The proof is simple enough. Represent the integer N in the moreor less standard fashion:N = d_k * 10^k + d_{k-1} * 10^{k-1} + ... + d_1 * 10 + d_0where d_i are in the set {0,1,2,3,4,5,6,7,8,9} and k >= 0.It is trivial to prove that10 % 3 = 1 [*]and almost as trivial to inductively prove that10^i % 3 = 1for all integers i >= 0.Therefore, N % 3 = (d_k + d_{k-1} + ... + d_1 + d_0) % 3.If (d_k + d_{k-1} + ... + d_1 + d_0) sums to a multipleof 3 or 9, as you hypothesize, then(d_k + d_{k-1} + ... + d_1 + d_0) % 3 = 0, and N % 3 = 0,and, with one obvious exception, N is therefore not prime.> > That is, in any base b, if the sum of the digits of any positive> number n add up to a multiple of any of the factors of (b - 1), then> that number is not prime.> > For example, in base 241, there is no prime number whose sum of the> digits add up to multiples of the digits represented by 2, 3, 4, 5, 6,> 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, or 240. (These digits> were written in base-10 for simplicitys sake. But they are indeed> single digits in base 241.)> > Ex., In base 241, the prime 65393 would be written 1,30,82. (Again,> digits in base 10 for simplicity.) The sum of those digits, 113,> isnt divisible by any of the factors of 240.The proof above is easily generalizable, although with base 241one runs into the issue you pointed out with the divisors of 240.(Note: 241 is prime, for what its worth.)> > --David[*] this notation should be familiar to most software engineers; the more traditional mathematical notation might be 10 = 1 (mod 3), and the = sign is actually a triple-equals, which ASCII does not have. Unicode apparently puts it in ≍ , which as far as Usenet is concerned is way out in the boonies... :-) use UTF-8 encoding therefor but that would just look weird to SLRN users.-- #191, ewill3@earthlink.netIts still legal to go .sigless. >> You know how in base 10, if the sum of the digits of any number add up> to a multiple of 3 or 9, then that number is not prime? Can it be> proven that it works in the general case? I know it to be true, but> dont know the proof.>> That is, in any base b, if the sum of the digits of any positive> number n add up to a multiple of any of the factors of (b - 1), then> that number is not prime.>> For example, in base 241, there is no prime number whose sum of the> digits add up to multiples of the digits represented by 2, 3, 4, 5, 6,> 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, or 240. (These digits> were written in base-10 for simplicitys sake. But they are indeed> single digits in base 241.)>> Ex., In base 241, the prime 65393 would be written 1,30,82. (Again,> digits in base 10 for simplicity.) The sum of those digits, 113,> isnt divisible by any of the factors of 240.>> --David Dene sd(x,b) = sum of digits of x in base b.Dene a == b (mod c) if c | (a-b), that is, standard modular congruence.Lemma: b^k == 1 (mod b-1)Proof: b^k - 1 = (b-1) * [ b^(k-1) + b^(k-2) + ... + b^1 + b^0 ] (geometric progression)Therefore (b-1) | (b^k - 1) Theorem: sd(x,b) == x (mod b-1)Proof:Let d_0, d_1, ... d_m be the digits of x, base b.x = d_0 * b^0 + d_1 * b^1 + ... + d_m * b^mx == d_0 * b^0 + d_1 * b^1 + ... + d_m * b^m (mod b-1)x == d_0 * 1 + d_1 * 1 + ... + d_m * 1 (mod b-1)x == d_0 + d_1 + ... + d_m (mod b-1)x == sd(x,b) (mod b-1)Corollary: If d | (b-1) and d | sd(x,b), then d | x.Proof:(b-1) = d * i (since k | (b-1))sd(x,b) = d * j (since k | sd(x,b))x - sd(x,b) = (b-1) * k (since x == sd(x,b) (mod b-1))x = sd(x,b) + (b-1) * kx = d*j + d*i*kx = d * (j + i * k)Therefore d | x.Corollary: If d | (b-1) and d | sd(x,b) and d != 1, then d is not prime.-- ------------------------Mark Jeffrey Tilfordtilford@ugcs.caltech.edu There is a recent book (2002) on numerical methods with an> accompanying numerical library [...]> Also unlike NR, I did not see restrictions on distributing the source> code.The point is not whether you see restrictions, but whether you see explicit *permission* to redistribute source. In the copyright law of most countries, including the US, the *default* is that redistribution of any sort is not permitted. > > The book is hardbound, has 842 pages, and comes with a CD-ROM> > containing the Fortran 77 and C computer code and its documentation.> . . . .> >Both Compaq Visual Fortran> > and Lahey/Fujitsu Fortran 95 can compile the single and> > double-precision versions, but only LF95 compiles the quadruple> > precision code. CVF 6.6 does not like (KIND=16), giving error messages> > Doesnt sound like Fortran 77 to me. But can you characterize the programs> in more detail? What can youfind in this book that is not adequately> treated in Numerical Recipes?The KIND declarations are used only in the quadruple precision code,not the single or double precision code. All of the single and doubleprecision code compiles with CVF, even when the F77 compiler driveris used. Almost all compile with g77. The author uses all capitalletters, xed format, DO-CONTINUE (rather then DO-ENDDO) loops, andhe says in the book that its Fortran 77.I dont think the book is a subset or superset of Numerical Recipes.One subject it covers that interests me and is not in NR isleast-squares spline FITTING (both books cover spline interpolation).I just got the book and cannot judge the quality of the code. As Isaid before, the author does not seem to restrict the distribution ofhis code (unlike NR). I see no copyright notice for the code, only thedisclaimerUsers are welcome to use these subprograms at their own risk.Here is a list of the programs. Chapter 2 Roundoff ErrorCASSUM Cascade sum of a nite series (using a function)CASSUM_A Cascade sum of a nite series (using an array)ROUND Rounding a oating-point number to specied no. of digits Chapter 3 Linear Algebraic EquationsGAUELM Solve a system of linear equations using Gaussian eliminationGAUELM_C Solve a system of linear eq. using Gaussian elimination(Complex version)MATINV Calculate inverse of a square matrix using GaussianeliminationCROUT Solve a system of linear equations using Crouts algorithmCROUT_C Solve a system of linear eq. using Crouts algorithm (Complexversion)CROUTH Iterative renement of solution of a system of linearequationsCHOLSK Solve a system of linear eq. with symmetric positive denitematrixGAUBND Solve a system of linear eq. with band matrix using GaussianeliminationGAUBND_C Solve a system of linear eq. with a band matrix (Complexversion)SVD Singular value decomposition of a matrixSVDEVL Solve a system of linear equations using SVD Chapter 4 InterpolationDIVDIF Interpolation and derivatives using divided differenceformulaDIVDIF0 Divided difference interpolation formula (no derivativesversion)NEARST Find nearest point in an ordered table using bisectionSPLINE Calculate coefcients of interpolating cubic splineSPLEVL Evaluate the cubic spline and its derivatives at a speciedpointSMOOTH Draw a smooth curve through a set of points using cubicsplineBSPLIN Calculate B-spline basis functions on a set of knotsBSPINT Calculate coefcients of B-spline interpolationBSPEVL Evaluate function value and its derivatives using B-splineexpansionRATNAL Calculate rational function interpolationPOLY2 Calculate polynomial interpolation in two dimensionsLINRN Calculate linear interpolation in n dimensionsLOCATE Find the bracketing subinterval in an ordered tableBSPINT2 Calculate coefcients of B-spline interpolation in 2dimensionsBSPEV2 Evaluate function value using B-spline expansion in 2dimensionsBSPINTN Calculate coefcients of B-spline interpolation in ndimensionsBSPEVN Evaluate function value using B-spline expansion infindimensionsBSPEVN1 Evaluate function & rst derivative using B-spline expansionin n dimensionsBSPEVN2 Evaluate function & derivatives using B-spline expansion in ndimensions Chapter 5 DifferentiationDRVT Differentiation using h --> 0 extrapolation Chapter 6 IntegrationSIMSON Integration using Simpsons 1/3 ruleSPLINT Integrate a tabulated function using cubic splineBSPQD Integrate a B-spline expansionROMBRG Romberg integrationEPSILN Integration using epsilon-algorithmGAUSS Integration using Gauss-Legendre formulaGAUCBY Integration using Gauss-Chebyshev formula(w(x)=1/SQRT((x-A)(B-x)))GAUCB1 Integration using Gauss-Chebyshev formula(w(x)=SQRT((x-A)/(B-x)))GAUCB2 Integration using Gauss-Chebyshev formula(w(x)=SQRT((x-A)*(B-x)))GAUSQ2 Integration over (0,A] with square root singularity usingGaussian formulasGAUSQ Integration over (0,A] using Gaussian formula withw(x)=1/SQRT(x)GAULAG Integration over semi-innite interval using GaussianformulasLAGURE Integration over semi-innite interval using Gauss-LaguerreformulaHERMIT Integration over innite interval using Gauss-HermiteformulaGAULG2 Integration over (0,A] with logarithmic singularity usingGaussian formulasGAULOG Integration over (0,A] using Gaussian formula withw(x)=LOG(A/x)GAUSRC Weights and abscissas of Gaussian formula using recurrencerelationGAULEG Weights and abscissas of Gauss-Legendre quadrature formulasGAUJAC Weights and abscissas of Gauss-Jacobi quadrature formulasLAGURW Weights and abscissas of Gauss-Laguerre quadrature formulasGAUHER Weights and abscissas of Gauss-Hermite quadrature formulasGAUSWT Weights and abscissas of Gaussian formula using moments ofweight functionFILON Integration of an oscillatory function using Filons formulaADPINT Adaptive integration over a nite intervalKRONRD Integration using Gauss-Kronrod formula for use with ADPINTGAUS16 Integration using 16 point Gauss-Legendre formula for usewith ADPINTCAUCHY Calculate Cauchy principal value of an integralEULER Summation of alternating series using Euler transformationBSPQD2 Integrate a B-spline expansion in 2 dimensionsBSPQDN Integrate a B-spline expansion in N dimensionsMULINT Multiple integration using product Gauss rule with varyingno. of pointsNGAUSS Multiple integration using a specied product Gauss ruleSPHND To convert from hyper-spherical coordinates to CartesiancoordinatesSTRINT Multiple integration using monomial rules with varying no. ofpointsSTROUD Multiple integration using a specied monomial ruleMCARLO Multiple integration using Monte Carlo methodRAN Generate a sequence of random numbers with uniformdistributionRANF Generate a sequence of random numbers with uniformdistributionRANGAU Generate a sequence of random numbers with GaussiandistributionEQUIDS Multiple integration using equidistributed sequences Chapter 7 Nonlinear Algebraic EquationsBISECT Solve a nonlinear equation using bisectionSECANT Solve a nonlinear equation using secant iterationSECANC Solve a nonlinear equation using secant iteration (complexversion)SECAN_2 Solve a nonlinear eq. using secant iteration, function ofform F*2**IXSECANC_2 Solve a nonlinear eq. using secant iteration, complexfunction F*2**IXSECANI Solve a nonlinear eq. using secant iteration (with reversecommunication)NEWRAP Solve a nonlinear equation using Newton-Raphson methodBRENT Solve a nonlinear equation using Brents methodSEARCH Locate complex zeros by looking for sign changesZROOT Complex roots of a nonlinear equation with deationZROOT2 Complex roots of a nonlinear equation, function value of formF*2**IXMULLER Complex root using Mullers methodMULER2 Complex root using Mullers method with function in a scaledformDELVES Complex zeros of an analytic function using quadrature basedmethodCONTUR Contour integration over a circular contour for DELVESNEWRAC Complex root of a nonlinear equation using Newton-RaphsonmethodPOLYR All roots of a polynomial with real coefcientsLAGITR Root of a polynomial with real coefcients using LaguerresmethodPOLYC All roots of a polynomial with complex coefcientsLAGITC Root of a polynomial with complex coefcients usingLaguerres methodDAVIDN Solve a system of nonlinear eq. using Davidenkos method(with NEWTON)DAVIDN_B Solve a system of nonlinear eq. using Davidenkos method(with BROYDN)NEWTON Solve a system of nonlinear equations using Newtons methodBROYDN Solve a system of nonlinear equations using Broydens method Chapter 8 OptimisationBRACKM Bracketing a minimum in one dimensionGOLDEN Minimisation in one dimension using golden section searchBRENTM Minimisation in one dimension using Brents methodDAVIDM Minimisation in one dimension using cubic HermiteinterpolationBFGS Minimisation in n dimensions using quasi-Newton method (BFGSformula)LINMIN Line search for quasi-Newton methodFLNM Calculate the function value for line search for quasi-NewtonmethodNMINF Minimisation in n dimensions using direction set methodLINMNF Line search for direction set methodFLN Calculate the function value for line search for NMINFSIMPLX Solve a linear programming problem using simplex methodSIMPX Simplex method for a LP problem in the standard form Chapter 9 Functional ApproximationsPOLFIT Least squares polynomial t using orthogonal polynomialsPOLEVL Evaluate the tted polynomial and its derivatives at aspecied pointPOLFIT1 Least squares polynomial t using orthogonal polynomials,simplied versionPOLORT Evaluate the orthogonal polynomial basis functions at a givenpointPOLFIT2 Least squares polynomial t using orthogonal polynomials in2 dimensionsPOLEV2 Evaluate the tted polynomial at a specied point in 2dimensionsPOLFITN Least squares polynomial t using orthogonal polynomials inn dimensionsPOLEVN Evaluate the tted polynomial at a specied point infindimensionsPOLEVN1 Evaluate the tted polynomial & its rst derivative in NdimensionsPOLEVN2 Evaluate the tted polynomial & 1st & 2nd derivatives infindimensionsLLSQ Linear least squares t in n dimensions: user dened set ofbasis functionsBSPFIT Least squares t to B-spline basis functions in onedimensionBSPFIT2 Least squares t to B-spline basis in 2 dimensions withequal weightsBSPFITW2 Least squares t to B-spline basis in 2 dimensions witharbitrary weightsBSPFITN Least squares t to B-spline basis in N dimensions withequal weightsBSPFITWN Least squares t to B-spline basis in N dimensions witharbitrary weightsNLLSQ Calculate Chi square function for a nonlinear least squarest with BFGSNLLSQ_F Calculate Chi square function for a nonlinear least squarest with NMINFDFT Discrete Fourier transform of complex data with arbitrary no.of pointsFFT Fast Fourier transform of complex dataFFTR Fast Fourier transform of real dataFFTN Fast Fourier transform of complex data in n dimensionsLAPINV Inverse Laplace transformPOLD Evaluate a polynomial and its derivatives at any pointRMK Evaluate a rational function at any pointRMK1 Evaluate a rational function (constant term in denominator 1)RMKD Evaluate a rational function and its derivative at any pointRMKD1 Evaluate a rational function & derivative (constant term indenominator 1)PADE Calculate coefcients of Pade approximationsCHEBCF Convert from power series to Chebyshev expansion and viceversaCHEBEX Calculate the coefcients of Chebyshev expansionCHEBAP Rational function approximation using Chebyshev polynomialsREMES Minimax approximation to mathematical functions using RemesalgorithmFM Calculate error in rational function real XERF Calculate Error function at real XERFC Calculate complementary Error function at real XBJ0 Calculate Bessel function of rst kind of order zeroBJ1 Calculate Bessel function of rst kind of order oneBJN Calculate Bessel function of rst kind of integral orderBY0 Calculate Bessel function of second kind of order zeroBJY0 Calculate Bessel function of rst and second kind of orderzeroBY1 Calculate Bessel function of second kind of order oneBJY1 Calculate Bessel function of rst and second kind of orderoneBYN Calculate Bessel function of second kind of integral orderSPHBJN Calculate spherical Bessel function of integral orderBI0 Calculate modied Bessel function of rst kind of orderzeroBI1 Calculate modied Bessel function of rst kind of order oneBIN Calculate modied Bessel function of rst kind of integralorderBK0 Calculate modied Bessel function of second kind of orderzeroBK1 Calculate modied Bessel function of second kind of orderoneBKN Calculate modied Bessel function of second kind of integralorderDAWSON Calculate the value of Dawsons integralFERMM05 Calculate the Fermi integrals for k=-1/2FERM05 Calculate the Fermi integrals for k=1/2FERM15 Calculate the Fermi integrals for k=3/2FERM25 Calculate the Fermi integrals for k=5/2PLEG Calculate the Legendre polynomial of degree L at XPLM Calculate the associated Legendre functionsYLM Calculate the spherical harmonic (theta, phi as arguments)YLM_X Calculate the spherical harmonic (Cos(theta),phi asarguments)MINMAX Rational function minimax approximation to discrete dataPOLYL1 Polynomial L1-approximation to discrete dataLINL1 Linear L1-approximation to discrete data for arbitrary basisfunctionsSIMPL1 Modied simplex method for LP problems in L1-approximation Chapter 10 Algebraic Eigenvalue ProblemINVIT Eigenvalue and eigenvector using inverse iterationINVIT_L Eigenvalue and left-eigenvector using inverse iterationINVIT_C Eigenvalue and eigenvector using inverse iteration (Complexeigenvalues)INVIT_CL Complex eigenvalue and left-eigenvector using inverseiterationINVIT_CC Eigenvalue and eigenvector using inverse iteration forcomplex matrixTRED2 Reduction of a real symmetric matrix to symmetric tridiagonalformTRBAK Back-transform eigenvectors of tridiagonal matrix to originalmatrixTQL2 Eigenvalue problem for symmetric tridiagonal matrix usingQL-algorithmTRIDIA Eigenvalues & eigenvectors of sym. tridiagonal matrix usingSturm sequenceSTURM Eigenvalues of symmetric tridiagonal matrix using SturmsequenceTINVIT Eigenvalue & eigenvector of sym. tridiagonal matrix usinginverse iterationHEREVP Eigenvalue problem for a complex Hermitian matrixBALANC Balancing a general real matrixBALBAK Back-transform eigenvectors of balanced matrix to originalmatrixBALBAK_L Back-transform left-eigenvectors of balanced matrix tooriginal matrixELMHES Reduce a real matrix to Hessenberg form using GaussianeliminationHQR Eigenvalues of a Hessenberg matrix using QR-algorithm Chapter 11 Ordinary Differential EquationsRKM Initial value problem : 4th order Runge-Kutta method withadaptive step sizeRKM_2 Initial value problem : 2nd order Runge-Kutta method withadaptive step sizeRK4 One step of integration using fourth-order Runge-Kutta methodRK2 One step of integration using second-order Runge-Kutta methodMSTEP Initial value problem using multistep method with fourth-order Adams methodSTRT4 Starting values for multistep method using Runge-Kutta methodGEAR One step of integration using fourth-order stify stablemethodEXTP Initial value problem using extrapolation method FDM Two-point boundary value problem using nite differencemethodGEVP Eigenvalue problem in differential equations using nitedifferencesGEVP_C Eigenvalue problem in ODE using nite differences (Complexversion)GAUBLK Solve a system of linear equations involving nitedifference matrixGAUBLK_C Solve a system of linear eq. for complex nite differencematrixSETMAT Generate nite difference matrix for a system ofdifferential eq.SETMAT_C Generate nite difference matrix for ODE (Complex version)BSPODE Two-point boundary value problem using expansion method withB-spline basis Chapter 12 Integral EquationsFRED Solve a Fredholm equation using quadrature methodFREDCO Solve a Fredholm equation using collocation methodFUNK =K(x,t)*Phi(j,t) for evaluating the integrals in collocationmethodRLS Solve a linear inversion problem using RLS techniqueFORW Solve the forward problemVOLT Solve a linear Volterra equation using trapezoidal ruleVOLT2 Solve a Nonlinear Volterra eq. of the second kind usingSimpsons rule Chapter 13 Partial Differential EquationsCRANK Linear second-order parabolic equations using Crank-NicolsonmethodLINES Nonlinear parabolic equations using the method of linesADM Parabolic eq. in two space variables using alternatingdirection methodLAX Nonlinear hyperbolic equations using the Lax-Wendroff methodSOR Solve linear second order elliptic equations using SOR methodADI Solve linear second order elliptic equations using ADI method One subject it covers that interests me and is not in NR is> least-squares spline FITTING (both books cover spline interpolation).You might be interested in the one in LLSQ, on netlib.> Here is a list of the programs.usual undergraduate numerical analysis textbook. And the lack of licensingrestrictions is indeed a plus. =The posted list of bugs on the authors web site is empty and was lastupdated in Feb. 2002. Such perfection is suspicious. I think Ill postponeordering this book until I hear some positive reviews. =I want to t some pure complex data x (only imaginary part) to some othercomplex data, y, by a polynomial with linear least squares.y=p0 T0(x) +p1 T1(x)+...+pn Tn(x)where Ti(x) represents the ith Chebyshev polynomial.(i thought this would provide me with better numerical conditioning,since i get Vandermonde system to solve).I need real coefcients in my polynomial, so i assume p0, ..., pn and the coefcients of Ti(x) have to be real,while x is complex. I calculate coefcients with (Ax=b)With left matrix A :Re(T0(x)) Re(T1(x)) .... Re(Tn(x))Im(T0(x)) Re(T1(x)) .... Re(Tn(x))... for all xunknown coefcients are X=[p0 p1 ... pn] And right columnvector vector b :Re(y)Imag(y)... for all yEvery equation is split in real and imaginary part to make coefcientsreal.And theres my problem. This orthogonal technique works well if x is realand scaled in [0,1], since Ti(x) doesnt return very high values (only between0 and 1). But if x is complex, this property is not longer valid !e.g. T2(x)=2x^2-1 if x=1*i then T2(x)=-3In fact, this method gets every sooner illconditioned than when i dontuse Chebyshev polynomials. Does anyone know what im doing wrong, or does this technique only workfor real data??Please help me.Alfred. =Speaking of partial differentiation can someone please check my answerbecause Im getting different answers every time I try these twoquestions!1) What is df/dt if f=x^4y^3 in which t=x^5+y^2 and t^2=x^2+y^3 (Ivenot used the t squared part which is bugging me).I get (8x^3*y^4+15x^8y^2)/10x^4y^2 which isnt very tidy2) What are the stationary points on:f= (x+y+1)^2 ----------- x^2+y^2 +1I got into a big mess using the quotient rule tofind the rst secondand mixed derivatives but got an answer of (0,-1) which is a saddlepointand h=cos (x+y)this seemed a bit bizzare as the df/dx and df/dy are equal but then I = 807175 22 Jul 1998The Black Hole Information Puzzle andEvidence for a Cosmological ConstantGerorge ChaplineLawrence Livermore National LaboratoryLivermore, CA 94507GC: Recent hints from observations of distant supernovae of a positive cosmological constant with magnitude comparable to the average density of matter seem to point in the direction of a two uid model for space-time; where the normal component consists of ordinary matter, while the superuid component is a zero entropy condensate.JS: In my model the normal uid is exotic w = -1 vacua. However, the small amount of ordinary matter Omega ~ 0.04 are solitonic/vortex cores of exotic vacua with non-trivial multiple connectedness and possibly extra space dimensions with positive pressure threaded by quantized gauge force ux quanta when projected down to 3D space.GC: Such a two uid model for space-time provides an immediate and simple explanation for why information seems to be lost when objects fall into a classical black hole. Recent observations [1] of Type I supernovae at cosmologically signicantredshifts have tended to conrm old suspicions [2] that the average density of matter issmaller than that required for a at (Omega =1) universe. In addition, these observations suggest that there is a positive cosmological constant whose magnitude is comparable to the average matter density. This last result is very surprising from the point of view of theoretical expectations based on either conventional quantum eld have been intensively investigated during the pa?6hlistrecoHptxelongfnt#shorfontTEXTGenevaptszfixd8listrecopjstenumleft(FIS HÊGeneva??. 7?1.01.01.01.0???????6!{?Ec frWEst~WEpf?ru?P¢stylnüISH?TABS?WDTH¸jstf?rct?lct?PRopB Kco[YAcute]?&?H[YAcute]?&???1Ú2[YAcute]???h[YAcute]?[Capi talAGrave]&?[YAcute]??&?´[YAcute]????[YAcute]? !??[YAcute]?!??[YAcute]?!?[YAcute]?!?À[YAcute]?&!?L[YAcu te]?2!?t[YAcute]?x!?- there are now theoretical grounds to suspect that a theory of quantum gravity like that of ref.3 actually has a positive vacuum energy. In fact because the model of ref.3 also requires that on average space be at, in the absence of matter this vacuum energy must have the critical value rhoc = 3H^2 /8piG, where H is the usual Hubble constant. The model for quantum gravity proposed in ref.3 has the additional feature that the ground state is a superuid-like state whose order parameter y can, following the hint of ref.4 that the vacuum energy is positive, be tentatively identied with the cosmological constant / / = 3H^2|PSI|^2 (1)JS: I am not sure what unit conventions George is using. My formula is, in contrast,/ = (Quantized Area)^2[(Quantized Volume)|PSI|^2 [CapitalEth] 1]Where/ ~ (H/c)^2GC: As is usual in a theory with a condensate ground state [5] we expect that the orderparameter of the condensate will slowly decrease as the entropy of the universe isincreased. On the other hand if the entropy is not too large the universe will remain at on macroscopic scales so thatOmegam + Omega/ = 1 (2).83 In this letter we would rst of all like to point out that the recent measurements ofthe brightness and redshift of distant supernovae can be taken as evidence in support of acondensate model for the vacuum state of quantum gravity with order parameter satisfying equations (1) and (2). Secondly, the assumption that the energy density associated with nite entropy represents collective excitations of the condensate vacuum leads to a very simple resolution of perhaps the most perplexing enigma of contemporary theoretical physics; namely, although to an outside observer information appears to be lost when objects fall into a classical black hole, to a freely falling observer nothing extraordinary appears to happen upon crossing the event horizon of a black hole [6].Actually our proposed resolution of this paradox is closely related to the fact that theintroduction of a condensate vacuum for quantum gravity also yields an explanation for an old cosmological puzzle: why is the observed entropy of the universe so low ? In particular the observed entropy of the universe is vastly smaller than what one would at least naively expect in any local eld theory of gravity with innumerable short distance degrees of freedom. Of course local quantum eld theories of gravity have many other difculties, and one might think that the entropy puzzle is simply a reection of these other difculties. However, the observed entropy is also much smaller than what is expected in superstring theories whose ground states have continuous moduli. The author has previously noted [7] that the entropy puzzle suggests that in reality the universe is in a nearly pure quantum state (which necessarily has nearly zero entropy).JS: I agree with George on this. I had this general idea independently of George and it is in my two books Destiny Matrix and Space-Time and Beyond II (2002), but George had the idea before me by about 3 years or so.To be continued. =Ed Witten has been losing sleep over the cosmological constant puzzle. George Chaplines formula is/ = 3H^2|PSI|^2JS: I am not sure what unit conventions George is using. My formula is, in contrast,/ = (Quantized Area)^-2[(Quantized Volume)|PSI|^2 [CapitalEth] 1]Where/ ~ (H/c)^2Note the loop quantum gravity observables Quantized Area and Quantized Volume/ is Einsteins Cosmological ConstantRelation to string theory is(Quantized Area)/hc = (String Tension)^-1 = Wittens AlphaEd can now sleep easy. :-) Rationals are Uncountable> > Let S be the set of all rational numbers [0,1).> s is a member of S if 0.000... <= s < 1.000...> and s is rational.> > Assume s is represented in base factorial (!).> Base ! is used because every rational number> has a nite representation in base !.> > In base ! the allowable digits for> position k are (0,1,...,k).> (k starts at 1)> > Every position, k, represents 1 / (k+1)!.> > k> 1 1/2! = 1/2> 2 1/3! = 1/6> 3 1/4! = 1/24> > .123 (base !) = 1/2 + 2/6 + 3/24 = 0.958333... (base 10).> > Every rational number has an unique nite base !> representation. Any nite base ! number is rational.> > We can create the set S dened above by taking the> set produced by counting in base !.> > .0> .1> .01> .11> .02> .12> .001> .101> ...> > There exists a rational number, x, not in S.Asserted without basis.> If S(i) is of the form .111...1 and> its length is equal to or greater than x> then set x to a string of 1s one longer than S(i).i = ....> x differs from every member of S.> x is a rational number because it has a nite number> of digits. The length of x is exactly one greater> than some member of S.Lots of members of S have a length exactly one greater than some (other)member of S. In fact, all but the rst two members of your list havesuch a length.> 0.0 <= x < 1> > x = 1/2! + 1/3! + ... + 1/k!Then xs position on your list is (k-1)! + (k-2)! + ... + 2! + 2 (andobviously does not differ from that member of S).> and equals the largest rational number> less than the fractional part of e.No such number exists. You might as well talk about the smallestrational number greater than 0.-- Daniel W. Johnsonpanoptes@iquest.nethttp://members.iquest.net/~panoptes /039 53 36 N / 086 11 55 WX-Cise: tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oft =In PM, Russell Easterly said:>There exists a rational number, x, not in S.No.>x differs from every member of S.No. It just differs from the rst I elements.>the largest rational number less than the fractional part of e.There is no such number.-- Shmuel (Seymour J.) Metz, SysProg and JOATnot reply to =Please look hare: http://www.geocities.com/complementarytheory/ NewDiagonalView.pdfDoron Shadmi---= 19 East/West-Coast Specialized Servers - Total Privacy via Encryption =--- are Uncountable Youve certainly given this some thought, but might I suggest next> time try to prove something not trivially false.To paraphrase Animal Farm:Some things are less trivial than others.>Let S be the set of all rational numbers [0,1).>s is a member of S if 0.000... <= s < 1.000...>and s is rational. Fine.Assume s is represented in base factorial (!).>Base ! is used because every rational number>has a nite representation in base !.In base ! the allowable digits for>position k are (0,1,...,k).>(k starts at 1)Every position, k, represents 1 / (k+1)!.k>1 1/2! = 1/2>2 1/3! = 1/6>3 1/4! = 1/24.123 (base !) = 1/2 + 2/6 + 3/24 = 0.958333... (base 10).Every rational number has an unique nite base !>representation. Any nite base ! number is rational. Yes but you also assume a special form for the base-! representation> that you really should prove to be i) unique ii) cover all rationals> between 0 and 1. Ill take it as given for now.Several people in this newsgroup have given proofs of this.Base ! has nite representations for all rationalsbecause the power series (actually, the product series = N!)contains every power of a prime.>We can create the set S dened above by taking the>set produced by counting in base !..0>.1>.01>.11>.02>.12>.001>.101>...There exists a rational number, x, not in S. I suppose between 0 and 1, otherwise this is not relevant.Yes.>If S(i) is of the form .111...1 and>its length is equal to or greater than x>then set x to a string of 1s one longer than S(i). What is S(i)? The largest number whose base-! representation consists> of all ones? It doesnt exist! Your denition creates a set that> includes among other things all numbers of the form: S(i) = Sum(k:2->i, 1/k!) where i is in N. The only number *not* in the list is the limit of> said sum as i tends towards innity, which converges to the> irrational number e - 2.I am dening a method to compute x.x will be a nite approximation of e-2.x is not equal to e-2.> In fact, the unique representation of rationals in base-! is one way> of showing there exists a bijection from N to Q.Actually, it is the smallest rational approximation of e that is not inset>S where a rational approximation of e is any number of the form.111...111. In other words, the maximum of an open set. It does not exist.Is this really an open set? S is supposed to containALL of the rational approximations of e-2.Isnt this the same thing as saying S contains e-2?Let me make three assumptions:1) I can examine every member, S(i), of S.2) I can determine if S(i) is less than, equal to, or greater than S(j).3) S contains every rational approximation of e-2 (of form .111...1 inbase!)I dene a method to calculate the largest rational approximation ofe-2 in S:x=0For i=0 to ?: If S(i) is of the form .111...1 and S(i) is larger or equal to x then x= S(i).Clearly, if I can examine every member of S then I can compute x.One of my three assumptions must be false.Which one?Russell- 2 many 2 count Youve certainly given this some thought, but might I suggest next> time try to prove something not trivially false.> > To paraphrase Animal Farm:> Some things are less trivial than others.But since it is so simple to construct injections from the rationals, Q, to the naturals, N, if you continue to insist that the rationals, Q, are uncountable, you must also accept that the naturals, N, are uncountable.The following generates innitely many injections from Q to N, depending on the choices of u and v:Let x be any member of Q and let n(x) and d(x) be the numerator and denominator of the standard form or lowest terms representation of x as the fraction n(x)/d(x), and let u and v be any two relatively prime naturals greater than 1, then f(x) = u^n(x)*v^d(x) if x >=0 = u^n(-x)*v^d(-x) if x < 0injects Q into N. Russell Easterly>> What is S(i)? The largest number whose base-! representation consists>> of all ones? It doesnt exist! Your denition creates a set that>> includes among other things all numbers of the form:>> S(i) = Sum(k:2->i, 1/k!)>> where i is in N. The only number *not* in the list is the limit of>> said sum as i tends towards innity, which converges to the>> irrational number e - 2.I am dening a method to compute x.Methods of computing something are pointless when it doesnt exist.This was covered in another thread.>x will be a nite approximation of e-2.>x is not equal to e-2.Then x is in S by denition.>> In other words, the maximum of an open set. It does not exist.Is this really an open set? S is supposed to contain>ALL of the rational approximations of e-2.Not open in the usual sense of the word, but every irrational numberbetween 0 and 1 is a limit point of S and therefore has no largestrational approximation. So whatever you consider to be a rationalapproximation of e-2 that is between 0 and 1 is in S, yes.>Isnt this the same thing as saying S contains e-2?Absolutely not. S contains the Cauchy sequence that denes e-2. Itcannot contain e-2 since its not rational and your set only containsrationals by denition.>Let me make three assumptions:1) I can examine every member, S(i), of S.Dene examine. S is an innite set.>2) I can determine if S(i) is less than, equal to, or greater than S(j).Yes. The rationals in [0, 1) are well-ordered.>3) S contains every rational approximation of e-2 (of form .111...1 in>base!)Yes.>I dene a method to calculate the largest rational approximation of>e-2 in S:x=0>For i=0 to ?:> If S(i) is of the form .111...1 and S(i) is larger or equal to x> then x= S(i).Your algorithm fails to halt. Even if it did halt, it would only everprint out a rational we know to be in S.>Clearly, if I can examine every member of S then I can compute x.>One of my three assumptions must be false.>Which one?That computability has anything to with this. On S(i)? The largest number whose base-! representation consists>> of all ones? It doesnt exist! Your denition creates a set that>> includes among other things all numbers of the form:>> S(i) = Sum(k:2->i, 1/k!)>> where i is in N. The only number *not* in the list is the limit of>> said sum as i tends towards innity, which converges to the>> irrational number e - 2.I am dening a method to compute x. Methods of computing something are pointless when it doesnt exist.> This was covered in another thread.x will be a nite approximation of e-2.>x is not equal to e-2. Then x is in S by denition.Unless the denition of S leads to contradiction.>> In other words, the maximum of an open set. It does not exist.Is this really an open set? S is supposed to contain>ALL of the rational approximations of e-2. Not open in the usual sense of the word, but every irrational number> between 0 and 1 is a limit point of S and therefore has no largest> rational approximation. So whatever you consider to be a rational> approximation of e-2 that is between 0 and 1 is in S, yes.Isnt this the same thing as saying S contains e-2? Absolutely not. S contains the Cauchy sequence that denes e-2. It> cannot contain e-2 since its not rational and your set only contains> rationals by denition.There is another way to dene e-2?>Let me make three assumptions:1) I can examine every member, S(i), of S. Dene examine. S is an innite set.2) I can determine if S(i) is less than, equal to, or greater than S(j). Yes. The rationals in [0, 1) are well-ordered.See Dave Seamans reply.I am not requiring S to be well-ordered.Supposedly, the rationals can be well ordered,but not by value.>3) S contains every rational approximation of e-2 (of form .111...1 in>base!) Yes.I dene a method to calculate the largest rational approximation of>e-2 in S:x=0>For i=0 to ?:> If S(i) is of the form .111...1 and S(i) is larger or equal to x> then x= S(i). Your algorithm fails to halt. Even if it did halt, it would only ever> print out a rational we know to be in S.Are you saying that assumption (1) is invalid?I cant examine every member of S?Russell- 2 many 2 count Yes. The rationals in [0, 1) are well-ordered.Not by the standard ordering.-- Dave SeamanJudge Yohns mistakes revealed in Mumia Abu-Jamal ruling. = Rationals are Uncountable Then how do you explain the numerous _injective_ mappings one may> construct from Q to N?I cant.I even give such a mapping for the set [0,1).> It is trivial to show that f is injective, thus the cardinality of the> rationals cannot be larger than that of the naturals.True.This same proof shows the naturals are uncountable.Russell- 2 many 2 count 01:44:40 -0800, Russell Easterly> This same proof shows the naturals are uncountable.The naturals cannot be put into a one-to-one correspondence withthemselves?No, no, no! Youve got it all wrong! Youre confusing a thing anditself. --- attributed to Marvin Minsky-- http://hertzlinger.blogspot.com = > Rationals are Uncountable Then how do you explain the numerous _injective_ mappings one may> construct from Q to N?> > I cant.> I even give such a mapping for the set [0,1).> > It is trivial to show that f is injective, thus the cardinality of the> rationals cannot be larger than that of the naturals.> > True.> This same proof shows the naturals are uncountable.Since countable means can be put into one to one correspondence with the naturals, Russell in in deep dodo when he claims that any set cannot be put into one to one correspondence with itself.Since this contradiction only arises from Russsells claim that the rationals are uncountable, every sane person will reject that claim.What Russell will do remains to be seen. = > Rationals are Uncountable Then how do you explain the numerous _injective_ mappings one may> construct from Q to N?> > I cant.> I even give such a mapping for the set [0,1).> > It is trivial to show that f is injective, thus the cardinality of the> rationals cannot be larger than that of the naturals.> > True.> This same proof shows the naturals are uncountable.> Well, its not a proof since it contains the errors that others havepointed out. But I do wish people would stop saying things like youcant prove false things or you shouldnt attempt to. Im not very surethat mathematics is consistent. So, if there is a proof of statementS and someone comes along with a proof of the negation of S and bothproofs are valid, then mathematics is doomed. Fortunately, your proofshave obvious errors.> > Russell> - 2 many 2 count =Well, its not a proof since it contains the errors that others have>pointed out. But I do wish people would stop saying things like you>cant prove false things or you shouldnt attempt to. Im not very sure>that mathematics is consistent. So, if there is a proof of statement>S and someone comes along with a proof of the negation of S and both>proofs are valid, then mathematics is doomed. Doomed? I would thinkfinding two such proofs would be the begining of a mostenlightening period for mathematics. Unless, of course, *every* valid proof ofS could somehow be turned into a valid proof of ~S. A small dose onconsistency could be a very good thing. rich =JS: I am not sure what unit conventions George is using. My formula is, in contrast,/ = (Quantized Area)^2[(Quantized Volume)|PSI|^2 [CapitalEth] 1]should be/ = (Quantized Area)^-2[(Quantized Volume)|PSI|^2 [CapitalEth] 1] many enemies too quickly, and thankfully he did, for it was his> downfall.Did the National Bocialists have anything to do with this?> Nor did he read the history of Napolean and Moscow, instead> prefering to repeat history. Nor did Bush read the history of the> recent glorious Russian victory of Chechnia, preferring instead to> repeat such history in Iraqnam.I think he was inspired by the Yankee occupation of Dixie, a case ofclassic imperialism. Capitalist civilization went forth and crushed aworld view opposed to tolerance and free speech (e.g., the gagrule). The d@mn Yankees used state terrorism (Shermans march to thesea), which set off a cycle of violence in the form of the KKK andJesse James (who started out as a pro-slavery terrorist). There wereeven Yankee settlements on Dixie soil. Dubya himself is asecond-generation settler.-- http://hertzlinger.blogspot.com =In Littlewoods Miscellany, he has| (Via Dr A.E.Western) There was a Rent Act after 1914, and the|denition of when a house was subject to it was as follows (my notation| in brackets). The standard rent (R) was dened to be the rent in 1914|(R_0), unless this was less than the rateable value (V), in which case it|was to be the rateable value. The house is subject to the act if either|the standard rent or the rateable value is less than (pounds) 105. There were|many law suits, argued ad hoc in each case. The subject is governed by|a fundamental theorem, unknown to the Law:|| Theorem: The house is subject to the act if and only if V < 105.||This follows from|| Lemma: Min{Max(R_0, V), V} = V.Keith Ramsay = Somewhere in the IRS forms [and this is no joke, its true] You may the thinking of the following, included as a ller in one of> the MAA journals some years back. [Anyone have the exact reference?] Someone dies, and his will makes some bequests, then ends by saying> after taxes are paid, any remaining money should be donated to> charity. Well, if charitible donations are tax-deductible, then the> amount of the donation effects the taxes. What to do? The I.R.S.> supposedly has a form where you do this computation, but it amounts> essentially to trial and error. In fact the problem can be solved by> high-school algebra. (Solution of a linear equation.) Or, not even> that: the problem can be solved using the method of false position:> that method is described in the Rind Papyrus, which dates from maybe> 2650 B.C. And some people say the I.R.S. is behind the times...The state of Indiana provided a table to compute their state income tax,but did not provide a formula.I gured out that the table was a straight percentage of income roundedto the nearest dime. Unfortunately, the table contained several errors.I contacted the state revenue ofce and was told I wouldhave to use the table even though it was wrong.I also had to compute a route tax for traveling salesmen.Salesmen were required to pay state and local taxes basedon the percentage of time they spent working in each state and town.Even the revenue ofce couldnt explain how to compute it.Russell- 2 many 2 count > But seriously, x does not exist is not the same thing as x is not>> computable.Hardline constructivists may disagree :-)I dont know of many hardline constructivists. I think there may besome variety of opinion on this issue. I dont know that I could quoteyou anybody who says x not existing and x not being computableare the same thing.Bishop had the following to say at the end of chapter 3 in his_Foundations of Constructive Analysis_: Brouwers contention that all elements of F(R,R) [functions from the reals to the reals] are continuous seems to contradict claims of certain recursive function theorists, who give examples of elements of F(R,R) that are not continuous. In both instances, the claims are based on extramathematical considerations. Brouwer analyzes all possible techniques for constructing elements f of F(R,R) and comes to the conclusion that all such f are continuous. The recursive function theorists analyze the possibilities for constructing real numbers, and come to the conclusion that they all possess a certain property (i.e., they are recursive). In addition, they show how to construct a discontinuous function on the set of recursive real numbers. These two positions are, in fact, compatible. They do not contradict each other, because it is possible to believe both (a) that all constructive real numbers are recursive and (b) that without making use of some unprovable hypothesis (such as the hypothesis that all constructive real numbers are recursive) the only elements of F(R,R) that can be constructed are continuous. Extramathematical considerations of both types (especially the rst) are useful in indicating that we should not try to do certain things constructively, but they have no place in the actual development of constructive mathematics.Keith Ramsay tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oft =In to prove that. Im saying that non-existence of a>solution implies the non-computability of a solution.>I dont know how to *prove* that though :)Its obvious - but not relevant.>The A that the OP was talking about was an *open* interval...That doesnt change anything. Rephrase his question to No, we cannot. Please tell me, if A is the interval (0,1), and current element is .5, what is the next smallest element?-- Shmuel (Seymour J.) Metz, SysProg and JOATnot reply to X-Cise: tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oft =In dened because if you tried to create a>Turing machine capable of computing this value it would not halt No, on multiple grounds. First, you dont need computing theory toshow that it doesnt exist. Second, if the TM doesnt halt then it isobviously *NOT* capable of computing this value. Third, things existthat are not computable, so you wouldnt have proven anythingrelevant. No, the minimum of an open interval doesnt exist because Ris an ordered eld.>So in computer science speak min(A) is uncomputable?In the sense that the Spanish Barber is uncomputable; you cantcompute something that doesnt exist in the rst place.>I guess Im trying to look at it from a computer science point of>view. Why would that be more fruitful than, e.g., trying to look at it froma Musical point of view?>As in, is it possible to create some operation, min, that applied to>some open interval (on the real line) returned an x s.t. x <= y for>all y in A. And the answer is no because of the above reasons.Wrong, the answer is yes, but it wouldnt have the properties that onewould like for a function with that name. Specically, min(A) notelement A, contrary to the behavior of the function that we normallyabbreviate as min. Add the condition min(A) element A and the answerbecomes no, but not for the reason that you give.-- Shmuel (Seymour J.) Metz, tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oft =In an algorithm> current element <-- next smallest elementThere is no such operation.>Now assuming we can alwaysfind a next smallest elementWhy not just assume that 2+2=5?>(which we can)No. There is no next smallest element in an ordered eld.-- Shmuel (Seymour J.) Metz, SysProg and JOATnot reply tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oft =In real line (R), ie. A = (a, b) with a>< b (where a, b in R). Now let x = min(A).Thats your problem right there. An open interval has no minimum; itonly has an innum (greatest lower bound). glb(A)=a is not an elementof A.>For example is it possible to dene a>variable with value>e = min(|x - y| : x, y in R and x != y)Same problem: it is *NOT* possible to dene that. The best that youcan do is to denee = glb(|x - y| : x, y in R and x != y)>min(A) - max(B)Same problem; only the second[1] exists. However,0 = glb(A) - lub(B) with a <= b < c, A = (b, c), B = [a, b][1] Because in the second case you specied a closed interval.-- Shmuel (Seymour J.) Metz, The consistent way to say, There is no absolute truth (How about this one?) ;o)> > THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT.> > George BuyanovskyIs that a Henkin sentence?-- http://hertzlinger.blogspot.com > The consistent way to say, There is no absolute truth (How about this> one?) ;o)> > THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT.> > George Buyanovsky> > 1. THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT.> 2. Statement 1. is true> > :)You are right; technically this joke does not work, however let us tryto modify your arrangement:1. THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUESTATEMENT.2. Statement THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUESTATEMENT is true3. Statement Statement THI . .. is true4.It seems that statements 2,3,4 are identical to statement 1.Probably the key of uncertainty is THIS STATEMENTGeorge The consistent way to say, There is no absolute truth (How about this one?) ;o)> > THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT.> > George BuyanovskyIf there were no truth, neither would there be any lies. If realityexists, then its existence is true, thus proving that truth exists. Ifreality doesnt exist, how could we be deceived into experiencing it?How can there be deception unless that deception masks a reality aboutwhich were being deceived? Either way, some kind of reality mustexist, thus proving something true. = <^> <(.87.87)> <^> ---- <^> <(.87.87)> buyanovsky@attbi.com (George Buyanovsky)> The consistent way to say, There is no absolute truth (How about this one?) ;o) THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT. George Buyanovsky If there were no truth, neither would there be any lies. If reality> exists, then its existence is true, thus proving that truth exists. If> reality doesnt exist, how could we be deceived into experiencing it?> How can there be deception unless that deception masks a reality about> which were being deceived? Either way, some kind of reality must> exist, thus proving something true.Tue true!Herc If there were no truth, neither would there be any lies. If reality> exists, then its existence is true, thus proving that truth exists. If> reality doesnt exist, how could we be deceived into experiencing it?> How can there be deception unless that deception masks a reality about> which were being deceived? Either way, some kind of reality must> exist, thus proving something true.I did not deny truth, those joke shows that it is amurky/subjective/relative subject. It is just properties of some model(our mind as well). However it is a banal but signicant percentageof non-stupid people still consider reality as an absolute entity. Itis a cozy simplication, which has the same root as any religion(sometimes they call it materialism). Certainly I am not free from thesame temptation but at least I see this.George The consistent way to say, There is no absolute truth (How about this one?) ;o)> > THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT.> > George Buyanovsky> > If there were no truth, neither would there be any lies. If reality> exists, then its existence is true, thus proving that truth exists. If> reality doesnt exist, how could we be deceived into experiencing it?> How can there be deception unless that deception masks a reality about> which were being deceived? Either way, some kind of reality must> exist, thus proving something true.One Day Tesshu, the famous swordsman and zen devotee, went to Dokuon and told him triumphantly he believed all that exists is empty, there is no you or me, and so on. The master, who had listened in silence, suddenly snatched up his long tobacco pipe and struck Tesshus head. The infuriated swordsman would have killed the master there and then, but Dokuon said calmly, Emptiness is quick to show its anger, isnt it? Forcing a smile, Tesshu left the room.(Soul Food -- Stories to Nourish the Spirit and the Heart Ed. Jack Korneld & Christina Feldman)Accept the terrible truth that all is illusion. All being One, wherever you go, there you are. But that doesnt have to ruin things. The Gnosis of illusion and what to do about it leadsthe seeker to Moksha-- experiential knowledge of the liberationfrom dualistic bondage. The choice after Moksha is your own. Return to source? To nothingness? Or choose the road for the sake of the undiscovered country and the experience of experiencefor the sake of itself. Accept the terrible truth and return to yourself. Your pathafter that crossroads is your own choice. =~)Students achieving oneness, will move ahead to twoness. (Woody Allen)We shall not cease from exploration. And the end of all our exploring Will be to arrive where we started Knowing the place for the rst time. (T.S. Eliot) The consistent way to say, There is no absolute truthYou said it already. Why do you need to say anything more?(How about this one?) ;o) THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT.>This statement is false if your rst statement is true.It seems you have been tortured by locking you up in a round room andtelling you that can only piss at a corner.> George Buyanovsky The consistent way to say, There is no absolute truth> > You said it already. Why do you need to say anything more?> > (How about this one?) ;o) THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT. > This statement is false if your rst statement is true.> > It seems you have been tortured by locking you up in a round room and> telling you that can only piss at a corner.Clarication for You:There is no absolute truth How about There is no absolute truth ?Is it absolute? George > > The consistent way to say, There is no absolute truth You said it already. Why do you need to say anything more? (How about this one?) ;o)> > THIS STATEMENT IS THE ONLY AND ONLY ONE ABSOLUTELY-TRUE STATEMENT.> > This statement is false if your rst statement is true. It seems you have been tortured by locking you up in a round room and> telling you that can only piss at a corner.> > Clarication for You:> > There is no absolute truth> How about There is no absolute truth ?> Is it absolute?> > GeorgeThat one is much more intriguing George:)Richard =Say i have a point p, and an arbitrary n-sided polygon. How can i tell howfar p is from any point (either vertex or edge) of the polygon? =| Here is another way to view this. You say there is only|one way to factor 49 which makes sense. Dik and others|here say there is another. It is dened by:|| w1(x) = GCD(a_1(x), 49)| w2(x) = GCD(a_2(x), 49)| w3(x) = GCD(a_3(x), 49),||where a_1(x), a_2(x), and a_3(x) are the roots of your|auxiliary polynomial,|| a^3 + 3*(-1 + 49*x)*a^2 - 49*(2401*x^3 - 147*x^2 + 3*x).||| Note that w1, w2, and w3 are perfectly well-dened:Keep in mind that the GCD is dened only up to multiplicationby units.|the |roots a_1, a_2, and a_3 exist and can be computed, and the |GCD function exists (by a deep theorem of Dedekind) and can |be computed.For example, if x=1,a_1(1) = -138.210434458... = 6375.47596375... * -0.0216784496160...a_2(1) = -31.3299394631... = 998.524028548... * -0.0313762499122...a_3(1) = 25.5403739215... = 0.00000769706133063... * 3318198.0530...where 6375.47596375..., 998.524028548..., and 0.00000769706133063...are the three roots of t^3-7374t^2+6366066t-49=0, and they multiplytogether to give 49,and-0.0216784496160..., -0.0313762499122..., 33189198.0530... are thethree roots of t^3-3318198t^2-176046t-2257=0. Since the polynomialst^3-7374t^2+6366066t-49 and t^3-3318198t^2-176046t-2257 are monicpolynomials with integer coefcients, their roots are of coursealgebraic integers.That was sort of fun; let me try to do another. If x=2, we get (ugh,Ill mark places where a number is continued on the next line with like in C code)a_1(2) = -279.300354441... = 1016597193845414091969293355102867957348 409.048415... *-2.74740434197... * 10^{-40}a_2(2) = -63.3122938187... = 3574859564584023060416081070013097699574 371117492591974367421061.951584... *-1.77104282489... * 10^{-62}a_3(2) = 51.6126482600... = 1.34830513302... * 10^{-104} * 3827964975879016817625368936818067843946 6426613668209951263900140296253120450185 91493808304178435225834041.000...where the rst factors in each of these is a root of x^3- (3574859564584023060417097667206943113666 340410847694842324769471) x^2+ (3634192201747556708576802697957676247053 7456650480245362950679011731799555936769 95172533270978579455876911) x- 49(and the three roots obviously are algebraic integers multiplyingtogether to give 49) and the other factor in each is a root of x^3 - (3827964975879016817625368936818067843946 6426613668209951263900140296253120450185 91493808304178435225834041) x^2- (1051696759566469898052937474234752487358 853239615505188006778565836) x- 18626.The last root a_3(2)/w_3(2)=20995126...4041.000... is a littlesurprising to me, since it appears to be very close to being aninteger, although actually irrational. About 39 zeros after thedecimal point, apparently. Presumably theres a good reason forthat.Note that so far I havent run afoul of nonreal roots, or ofnonunique factorization in the algebraic integers of the formr1*a^2+r2*a+r3, where r1,r2,r3 are rational numbers. That couldblow up the numbers one has to deal with even bigger!Please excuse any typos I may have made.Keith Ramsay ...> > Here is another way to view this. You say there is only> > one way to factor 49 which makes sense. Dik and others> > here say there is another. It is dened by:> > w1(x) = GCD(a_1(x), 49)> > w2(x) = GCD(a_2(x), 49)> > w3(x) = GCD(a_3(x), 49),> > You must be careful. Strange enough, but with this denition it is not> certain that w1(x)*w2(x)*w3(x) = 49. I must admit I have wondered about that. That is partly why yesterday I produced another denition of w1, w2, and w3 based on the Magidin-Mckinnon result (in another thread,I believe).> My latest denition is a bit more> elaborate, but I think it is fool-proof (though probably not James-proof):> v1(x) = GCD(a_1(x) + 7, 49)> v2(x) = GCD(a_2(x) + 7, 49)> v3(x) = GCD(a_3(x) + 7, 49)> k3(x) = v1(x)*v2(x)*v3(x) ; can be a multiple of 49> g(x) = k3(x) / 49 ; the excess, must be distributed> k2(x) = GCD(v2(x), g(x)) ; the part in v2 of the excess> k1(x) = g(x) / k2(x) ; and the remainder in v1.> z3(x) = v3(x) ; this one is plain> w2(x) = v2(x) / k2(x) ; part of the excess removed> w1(x) = v1(x) / k1(x) ; the remaining excess removed> u(x) = z1(x)*z2(x)*z3(x)/49 ; must be a unit> w3(x) = z3(x) / u(x) ; force it off. More elaborate than I would have guessed. Nora B. Yes, a posted list would be good, to clarify for example whether you>count corner adjacencies (like UT and NM, or AZ and CO), and which >underwater boundaries (as between HI and AK, MN and MI, or RI and NY) >you treat as adjacencies. Without specifying a list you probably >wont get useful answers.HI and AK??? Theres a heck of a lot of international water between them. Or are you claiming American sovereignty over the whole NorthPacic?Robert Israel israel@math.ubc.caDepartment of Mathematics http://www.math.ubc.ca/~israel University of British Columbia Vancouver, BC, Canada V6T 1Z2 =|This is called Graph Covering in general, and what youre looking for |is a solution for the Minimum dominating set. Unfortunately, its an|NP problem.Being in NP is not a bad sign. All efciently solvable problems are inNP. What suggests its difcult is its being NP-complete, one of theNP problems to which all the others can be reduced in polynomial time.Keith Ramsay > > I am stuck in high school maths mode, and cant seem to get into> university level maths. This might be because I am entirely self> taught, but I dont know. Does anyone else have this problem?> > I am at a level where I understand most high school maths, and Ive> studied Calculus Made Easy. It would be helpful to have some kind of> way to check my knowledge.> > Does anyone know of any good textbooks that cover high school maths> with worked exercises, and any texts that help the transition from> high school maths to the more exciting stuff at university level? A> book that takes time to explain things, point out applications and say> why rather than just how. I am trying to understand maths, not just> learn some techniques or shortcuts.I see that youve signed off, but for the record, I would recommendVector_Spaces_Of_Finite_Dimension by G.C. Shephard, University Mathematical Texts ( 1966 ) ( This was a new book when I discoveredit my freshman year at Brown U. )This is a thin, terse treatment of linear algebra, but it is verymathy and emphasizes proof. The rst exercise is to prove thatlambda * o = o, where lambda is a scalar and o is the zero vectorof a vector space. You rst have to realize that this is notstated in the denition, then see how it follows from linearity.Of course, all the proofs depend on applying linearity, so youcan get in the swing of things by picking up on the idea.Lew Mammel, Jr. <3ff17881$0$4763$61fed72c@news.rcn.com> X-Cise: tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oft So much for politicians lip service about education being a national> priority.Are you sure that you dont live in the US? That comment would beright at home here.Q: How can you tell when a politician is lying?-- Shmuel (Seymour J.) Metz, SysProg and <3ff2df21$0$4759$61fed72c@news.rcn.com> X-Cise: tanbanso@iinet.net.auX-CompuServe-Customer: YesX-Coriate: admin@interspeed.co.nzX-Ecrate: tanandtanlawyers.comX-Pose: george_cox@btinternet.comX-Punge: Micro$oft Are you talking about something purely mathematical, Yes. The classical presentation of Euclidean Geometry relies heavilyupon compass and straightedge constructions. However, the physicallanguage mask purely Mathematical concepts. Every proof where the textsays draw or construct can be replaced with an equivalent proofusing purely Mathematical language, e.g., existential quantiers. Thephysical language helps to visual the concepts, except when it leadsthe reader astray.>No to both. ;)No.-- Shmuel (Seymour J.) Metz, SysProg