mm-128 I was listening to the radio a while ago and they were talking about aset theory. The theory basically said that everything belongs in aset, because if an element does not belong in a set, it belongs in theset of elements that do not belong in a set (does that make sense?).What is this theorem called? Does anyone have any resources on theweb for it?TarasPS: I hope what I have written above is correct/makes radio a while ago and they were talking about a> set theory. The theory basically said that everything belongs in a> set, because if an element does not belong in a set, it belongs in the> set of elements that do not belong in a set (does that make sense?).> What is this theorem called? Does anyone have any resources on the> web for it?> Taras PS: I hope what I listening to the radio a while ago and they were talking about a> set theory. The theory basically said that everything belongs in a> set, because if an element does not belong in a set, it belongs in the> set of elements that do not belong in a set (does that make sense?).> What is this theorem called? Does anyone have any resources on the> web for it?>Theres no such theorem.Whether thats so depends upon the brand of set theory.Its not so in ZFC, but it is so in NFAn easier way to express the same notion is everything is a member of theset that contains only itself. Even so, in ZFC, there are some boogie menthat refuse membership in any and all sets. In NF those boogie men areexterminated, ie denied a visa of existence.> PS: I hope what I have written above is correct/makes sense :)>Some. I suggest youfind a better source all makes sense. Thers is something called the universal set. Theuniversal set is the set of all object that we are concerned about at themoment. For example if car is not in the universal set then for this problemthere is no such thing as a car. Nothing that is not in the universal setexists. Now suppose the universal set, U, contains 1, 2, 3, 4, 5, 6, 7, 8,egg, and sponge. That is U = {1, 2, 3, 4, 5, 6, 7, 8, egg, sponge}. Nowsuppose set A = {1, 3,5,8, egg}--note that everything that is in is also inU. Now we can talk about A, the set that contains everything exact what isin A. (A is called A complement or A prime)In our case A = {2, 4, 6, 7,sponge).Notice that everything ( in U ) is either in A or not in A, that isA, by denition of A. In the statement everything belongs in a set,because if an element does not belong in a set, it belongs in the set ofelements that do not belong in a set when it says it belongs in the set ofelements that do not belong in a set it is referring to the complement ofthe set. I was listening to the radio a while ago and they were talking about a> set theory. The theory basically said that everything belongs in a> set, because if an element does not belong in a set, it belongs in the> set of elements that do not belong in a set (does that make sense?).> What is this theorem called? Does anyone have any resources on the> web for it?> Taras PS: I hope what I have written above is is something called the universal set. The> universal set is the set of all object that we are concerned about at the> moment.Makes sense yes. If its true, depends upon the brand of set theory. The universal set U = { x | x = x }Now in ZFC set theory, currently the most accepted brand, its not a set,its a class. If were a set, then U would be in U, but that wouldcontradict the axiom of regularity, so U cant be a set, nor can U belongto U> > I was listening to the radio a while ago and they were talking about a> set theory. The theory basically said that everything belongs in a> set, because if an element does not belong in a set, it belongs in the> set of elements that do not belong in a set (does that make sense?).> What is this theorem called? Does anyone have any resources on the> web for it?> > Taras> > PS: I hope what pointed out before there have been people who have been> attacking algebra itself in posts. Now it still bothers me that I was> the one person standing up to defend algebra itself from what I> noticed.The image of JSH as a stand up guy defending any part of mathemetics from the attacks of others is rather basic lemma:Given any factor g of a polynomial P(x), g=r+c, where c=g at x=0, so c> is a factor of the contant term P(0), while r=g-c, so it varies if g> varies. That simple lemma not only anchors my paper, and my proof of Fermats> Last Theorem, it can be used in lots of places. Now Ill use it with> the roots of y^3 + 3y - 2 Ifind its roots fascinating. > and the three roots are y_1 = (1+sqrt(2))^{1/3} - 1/(1+sqrt(2))^{1/3} y_2 = (1+sqrt(2))^{1/3}(-1+sqrt(-3))/2 - (-1-sqrt(-3))/2(1+sqrt(2))^{1/3} y_3 = (1+sqrt(2))^{1/3}(-1-sqrt(-3))/2 - (-1+sqrt(-3))/2(1+sqrt(2))^{1/3}As simple as they are you cant just take the roots and *look* at themto tell whether or not any one of them is coprime to 2. It is justimpossible.Yet I work that out and still I keep coming back, as the simplicityand elegance of those roots keeps calling me.Sure I know that the cuberoot is ambiguous, so depending on how youtake the cuberoot, you shift between the solutions, which is why youcant prove whether or not one of them is coprime to 2, but still itseems like there should be some way to see by looking.But there isnt.Given the impossibility of proving that none of them are coprime to 2,youd think that people objecting would sit back, but nope, they claimGalois Theory eliminates a possibility.But that cant be. Galois Theory is based on that shifting. Actually, they can neither prove nor disprove the assertion with thetools theyre using.> where the polynomial Im interested in is P(x) = x+1, which has the non-polynomial factor (1+x)^{1/3}.Letting g = (1+x)^{1/3}, at P(0), g=1^{1/3}, and choosing the solution 1, I have c=1, so r=g-1. (Some may worry about my choice for c, Ill come back to that later.)Now using the substitution g=r+1, with x=sqrt(2), with my roots, I> have y_1 = r+1 - 1/(r+1) y_2 = (r+1)(-1+sqrt(-3))/2 - (-1-sqrt(-3))/2(r+1) y_3 = (r+1)(-1-sqrt(-3))/2 - (-1+sqrt(-3))/2(r+1)so I have y_1 = (r^2 + 2r)/(r+1) y_2 = [(r^2 + 2r)(-1+sqrt(-3)) + 2sqrt(-3)]/2(r+1) y_3 = [(r^2 + 2r)(-1-sqrt(-3)) - 2sqrt(-3)]/2(r+1)So once again I found myself drawn to that simplicity, looking forsome way, some how to make the math denite to the eye--to make iteliminate a possibility on sight.But it doesnt. You cant look at those roots and tell.Theres just no way to limit the math in that way, and intellectuallyI know why:The math has the exibility to handle several possibilities. Forsome polynomials, none of roots would be coprime to integer factors ofthe constant term, while for others, like y^3 + 3y - 2, several arecoprime.But you have to use advanced techniques to prove it.Still something keeps drawing me back to stare at those roots, lookingfor what cannot be found--a limitation that I can see.Its like in physics where you have quarks that cant be pulled outone by one. You can determine theyre there experimentally in pairsor threesomes. You can bounce things off them, but you cant paper does rest fully on the following rather basic lemma:> > Given any factor g of a polynomial P(x), g=r+c, where c=g at x=0, so c> is a factor of the contant term P(0), while r=g-c, so it varies if g> varies.> > That simple lemma not only anchors my paper, and my proof of Fermats> Last Theorem, it can be used in lots of places. Now Ill use it with> the roots of> > y^3 + 3y - 2 Ifind its roots fascinating.You are again answering your own posts with narcissistic monologues instead of answering your critics. Ifyou had any integrity, you would deal with the challenges not carry on conversations with yourself. Talk toa mirror if you want, but why use a newgroup to talk to yourself.> and the three roots are> > y_1 = (1+sqrt(2))^{1/3} - 1/(1+sqrt(2))^{1/3}> > y_2 = (1+sqrt(2))^{1/3}(-1+sqrt(-3))/2 -> > (-1-sqrt(-3))/2(1+sqrt(2))^{1/3}> > y_3 = (1+sqrt(2))^{1/3}(-1-sqrt(-3))/2 -> > (-1+sqrt(-3))/2(1+sqrt(2))^{1/3} As simple as they are you cant just take the roots and *look* at them> to tell whether or not any one of them is coprime to 2. It is just> impossible.You dont have to just look. The observation that y_1 y_2 y_3 = 2 is sufcient to prove that each root isa divisor of 2 in the ring of algebraic integers and, since none of these is a unit, none are coprime to 2.> Yet I work that out and still I keep coming back, as the simplicity> and elegance of those roots keeps calling me.Didnt someone call you home once? If so, how come you came back?> Sure I know that the cuberoot is ambiguous, so depending on how you> take the cuberoot, you shift between the solutions,What the hell does that mean?> which is why you> cant prove whether or not one of them is coprime to 2,Oh yes, you can. The product of the roots, y_1 y_2 y_3 equals 2. Hence, each of the roots divides 2 in thering of algebraic integers. This is because the quotient equals the product of the other two roots and theproduct of two algebraic integers is an algebraic integer. Hence none of the roots are coprime to 2.> but still it> seems like there should be some way to see by looking. But there isnt.So what? If mathematicians could prove everything by looking they wouldnt need theorems and lemmas.> Given the impossibility of proving that none of them are coprime to 2,Hold it. This is proven by noting that the product of the roots, y_1 y_2 y_3, equals 2 and that each of theroots divides 2 in the ring of algebraic integers -- meaning the quotient is an algebraic integer. Hencenone of the roots are coprime to 2. QED> youd think that people objecting would sit back, but nope, they claim> Galois Theory eliminates a possibility.I dont.> But that cant be. Galois Theory is based on that shifting.> Actually, they can neither prove nor disprove the assertion with the> tools theyre using.Galois Theory isnt necessary in this case. Basic algebra does the trick. You wouldnt want to attackbasic algebra, would you?> So once again I found myself drawn to that simplicity, looking for> some way, some how to make the math denite to the eye--to make it> eliminate a possibility on sight. But it doesnt. You cant look at those roots and tell.As has been shown above, it isnt necessary to look at those roots and tell. None of them is coprime to2. You have been refuted, defeated, vanquished, humiliated, crushed, conquered, exposed and undone. Takedown your false proof and acknowledge your errors.> Theres just no way to limit the math in that way, and intellectually> I know why: The math has the exibility to handle several possibilities. For> some polynomials, none of roots would be coprime to integer factors of> the constant term, while for others, like y^3 + 3y - 2, several are> coprime.None of them are coprime. The product of all the roots, y_1 y_2 y_3, is equal to 2. Each root divides 2producing an algebraic integer quotient. Hence, in the ring of algebraic integers, none of the roots, countem again!, none is coprime to 2. Your claim is false.> But you have to use advanced techniques to prove it.You cant prove your claim at all, because it is false.> Still something keeps drawing me back to stare at those roots, looking> for what cannot be found--a limitation that I can see.The limitation is between your ears, not in your eyes.> Its like in physics where you have quarks that cant be pulled out> one by one. You can determine theyre there experimentally in pairs> or threesomes. You can bounce things off them, but you cant *see*> them.No, it isnt like quarks. It is like an LSD trip.> And theres such a need to see. James HarrisOpen your eyes. You have been shown the way. To paraphrase Samuel Johnson: I can give you a solution, but Icant give you an understanding.--There are two things you must never attempt to prove: the unprovable -- and the obvious.--Democracy: The triumph of popularity over exibility to handle several possibilities. For>some polynomials, none of roots would be coprime to integer factors of>the constant term, while for others, like y^3 + 3y - 2, several are>coprime.(I assume your talking about _algebraic integers_.) The constant term of y^3 + 3y - 2 is -2. If Y is _any_ root of y^3 + 3y - 2, then (-2)/Y is root of x^3 + 3x^2 + 4. Thats a monic polynomial, so (-2)/Y is an algebraic integer, and therefore Y divides -2 in the ring of algebraic integers. So Y in _not_ coprime to -2.>But you have to use advanced techniques to prove it.No, you dont. Solving cubics is not an advanced technique.>Still something keeps drawing me back to stare at those roots, looking>for what cannot be found--a limitation that I can see.Its like in physics where you have quarks that cant be pulled out>one by one. You can determine theyre there experimentally in pairs>or threesomes. You can bounce things off them, but you cant *see*>them.If thats not seeing (in physics), then what is?>And theres such a need to see.Yes. And (almost) everybody _does_.-- Thomas Wasell | Id love to go out with you, but Im having all the cuberoot is ambiguous, so depending on how you|> take the cuberoot, you shift between the solutions,||What the hell does that mean?it means that hes much closer to actually understanding somethingabout mathematics in this post than he has been in just about any ofhis other posts. hes still horribly mixed up, but theres animportant truth that he almost seems close to understanding here.|> But that cant be. Galois Theory is based on that shifting.|> Actually, they can neither prove nor disprove the assertion with the|> tools theyre using.||Galois Theory isnt necessary in this case.galois theory is highly relevant and perhaps crucial here.|> Its like in physics where you have quarks that cant be pulled out|> one by one. You can determine theyre there experimentally in pairs|> or threesomes. You can bounce things off them, but you cant *see*|> them.||No, it isnt like quarks. It is like an LSD trip.no, its in fact very much like quarks, and in a surprisingly deepway. but yes, its also like at a journal.> And Im waiting to hear further from them.Why wait? Everyone already knows whats going to happen. Theyregoing to reject it, and youre going to make excuses. Why not startrationalizing your failure *now* and get a head start?-- Wayne Brown | When your tails in a crack, you improvisefwbrown@bellsouth.net | if youre good enough. Otherwise you give | your pelt to the trapper.e^(i*pi) = -1 -- that the cuberoot is ambiguous, so depending on how you> |> take the cuberoot, you shift between the solutions,> |> |What the hell does that mean? it means that hes much closer to actually understanding something> about mathematics in this post than he has been in just about any of> his other posts. hes still horribly mixed up, but theres an> important truth that he almost seems close to understanding here.Why not enlighten the rest of us then? Evidently James isnt quite up toit, and you could perform a service by identifying the important truth healmost seems close to understanding.> |> But that cant be. Galois Theory is based on that shifting.> |> Actually, they can neither prove nor disprove the assertion with the> |> tools theyre using.> |> |Galois Theory isnt necessary in this case. galois theory is highly relevant and perhaps crucial here.It may be relevant, but it certainly isnt necessary or crucial in provingthat the roots of a monic polynomial with integer coefcients are divisorsof the constant term within the ring of algebraic integers.> |> Its like in physics where you have quarks that cant be pulled out> |> one by one. You can determine theyre there experimentally in pairs> |> or threesomes. You can bounce things off them, but you cant *see*> |> them.> |> |No, it isnt like quarks. It is like an LSD trip. no, its in fact very much like quarks, and in a surprisingly deep> way. but yes, its also like an lsd trip.Please provide an in-depth explanation. Why leave the less informed hangingwhen you are able to clarify why it is that proving/disproving coprimalitywithin the ring of algebraic integers is like quarks?> -->Looking forward to your follow-up, as I assume your post was not a hit andrun contribution.--There are two things you must never attempt to prove: the unprovable -- andthe obvious.--Democracy: The triumph of popularity over fully on the following rather basic lemma:>> >> Given any factor g of a polynomial P(x), g=r+c, where c=g at x=0, so c>> is a factor of the contant term P(0), while r=g-c, so it varies if g>> varies.>> That simple lemma not only anchors my paper, and my proof of Fermats>> Last Theorem, it can be used in lots of places. Now Ill use it with>> the roots of>> >> y^3 + 3y - 2 Ifind its roots fascinating.> >> and the three roots are>> >> y_1 = (1+sqrt(2))^{1/3} - 1/(1+sqrt(2))^{1/3}>> >> y_2 = (1+sqrt(2))^{1/3}(-1+sqrt(-3))/2 ->> >> (-1-sqrt(-3))/2(1+sqrt(2))^{1/3}>> >> y_3 = (1+sqrt(2))^{1/3}(-1-sqrt(-3))/2 ->> >> (-1+sqrt(-3))/2(1+sqrt(2))^{1/3}As simple as they are you cant just take the roots and *look* at them>to tell whether or not any one of them is coprime to 2. It is just>impossible.No, it is not impossible. It is amazingly trivial, as Keith Ramsaypointed out right after you posted them:NONE OF THEM ARE COPRIME TO 2. THEY ARE ALL DIVISORS OF 2:y_1*(y_1^2+3) = 2y_2*(y_2^2+3) = 2y_3*(y_3^2+3) = 2.Surely you agree with all three of those expressions, since they areall roots of y^3 + 3y - 2.So they are all divisors of 2, and since none of them are units, theyare none of them coprime to 2. Simple, nay, trivial. [.snip.]>Given the impossibility of proving that none of them are coprime to 2,it follows that red is blue, 0 is 1, and I am the Pope (who,therefore, is not catholic).>youd think that people objecting would sit back, but nope, they claim>Galois Theory eliminates a possibility.Not even Galois theory is needed here. ->THIS<- one is trivial. a reasoner as Mr. Smith? I answer as a deceased friend of mine used to answer on like occasions - A mans capacity is no measure of his power to do mischief. Mr. Smith has untiring energy, which does something; self-evident honesty of conviction, which does more; and a long purse, which does most of all. He has made at least ten publications, full of gures few readers can critize. A great many people are staggered to this extend, that they imagine there must be the indenite something in the mysterious all this. They are brought to the point of suspicion that the mathematicians ought not to treat all this with such undisguised contempt, at least. -- A Budget of Paradoxes, Vol. 2 p. 129 by Augustus de [.snip.]Nitpicking...The rst time you made the point, you correctly stated:>You dont have to just look. The observation that y_1 y_2 y_3 = 2 is sufcient to prove that each root is>a divisor of 2 in the ring of algebraic integers and, since none of these is a unit, none are coprime to 2. [.snip.]Later, you said, in several different versions, things like:>Oh yes, you can. The product of the roots, y_1 y_2 y_3 equals 2. Hence, each of the roots divides 2 in the>ring of algebraic integers. This is because the quotient equals the product of the other two roots and the>product of two algebraic integers is an algebraic integer. Hence none of the roots are coprime to 2.The last statement only follows once you add since none of them is aunit [in the ring of algebraic such a reasoner as Mr. Smith? I answer as a deceased friend of mine used to answer on like occasions - A mans capacity is no measure of his power to do mischief. Mr. Smith has untiring energy, which does something; self-evident honesty of conviction, which does more; and a long purse, which does most of all. He has made at least ten publications, full of gures few readers can critize. A great many people are staggered to this extend, that they imagine there must be the indenite something in the mysterious all this. They are brought to the point of suspicion that the mathematicians ought not to treat all this with such undisguised contempt, at least. -- A Budget of Paradoxes, Vol. 2 p. 129 by Augustus de [.snip.] Nitpicking... The rst time you made the point, you correctly stated: >You dont have to just look. The observation that y_1 y_2 y_3 = 2 is sufcient to prove that each root is>a divisor of 2 in the ring of algebraic integers and, since none of these is a unit, none are coprime to 2. [.snip.] Later, you said, in several different versions, things like: >Oh yes, you can. The product of the roots, y_1 y_2 y_3 equals 2. Hence, each of the roots divides 2 in the>ring of algebraic integers. This is because the quotient equals the product of the other two roots and the>product of two algebraic integers is an algebraic integer. Hence none of the roots are coprime to 2. The last statement only follows once you add since none of them is a> unit [in the ring of algebraic integers].off one or more repititions of the same, or similar, argument. I dont take it as nitpicking, by the way. Theargument is so short that there is no reason (or excuse) for it to be incomplete.--There are two things you must never attempt to prove: the unprovable -- and the obvious.--Democracy: The triumph of popularity over limit:lim |z + h|/hh -> 0where h is a real number and z is a h|/h> h -> 0 where h is a real number and z is a complex number>Let z = x + iy|z + h|/h = ((x+h)^2 + y^2)/h = (x^2 + am totally confused. I easily see why you say the limit is 1 if z= 0--you plug in 0 for z in |z+h | to get |h| etc... Now I know that youcant divide by 0 and so on but when I take the lim h-->0 of (x^2 + y^2)/h +2x + h where x = y =0 then I get lim h-->0 (0/h + 2*0 + h) = lim h-->0 (0 +0 + h) = limh-->0 (h) = 0 not 1. What is going on here?? > How to compute this limit:> > lim |z + h|/h> h -> 0> > where h is a real number and z is a complex number> Let z = x + iy> |z + h|/h = ((x+h)^2 + y^2)/h> = (x^2 + y^2)/h + 2x + h lim = oo if z /= 1. This limit dne! > How to compute this limit:> > lim |z + h|/h> h -> 0> > where h is a real number and z is a complex number> Let z = x + iy> |z + h|/h = ((x+h)^2 + y^2)/h> = (x^2 William, I am totally confused. I easily see why you say the limit is 1 ifz> = 0--you plug in 0 for z in |z+h | to get |h| etc... Now I know that you> cant divide by 0 and so on but when I take the lim h-->0 of (x^2 + y^2)/h+> 2x + h where x = y =0 then I get lim h-->0 (0/h + 2*0 + h) = lim h-->0 (0+> 0 + h) = limh-->0 (h) = 0 not 1. What is going on here??William missed the Sqrt() when calculating |z+h|...For z=0, the expression becomes |h|/h which is +/-1 depending on whether h>0or h<0. So the limit as h->0 does not exist, although separate limits existif we consider h->0 from above or from below.When z /= 0, we have a similar situation but this time the expression tendsto +/- innity if h->0 from above or below respectively.Mike.ps. I think top-posting is frowned upon here! (doesnt worry me too muchthough..)> > How to compute this limit:> > lim |z + h|/h> h -> 0> > where h is a real number and z is a complex number> > Let z = x + iy> |z + h|/h = ((x+h)^2 + y^2)/h> = (x^2 + y^2)/h + 2x + h> > lim = oo if z |h|/h) = 1. This limit dne!> > How to compute this limit:> > lim |z + h|/h> h -> 0> > where h is a real number and z is a complex number> > Let z = x + iy> |z + h|/h = ((x+h)^2 + y^2)/h> = (x^2 + y^2)/h + 2x + h> > lim = oo if z /= 0> = 1 if z = 0Top posting is very confusing.Lets consider lim h->0 (|h|/h).Suppose h is really really small, like 1/zillion. Then |h| is 1/zillion and h is 1/zillion and |h|/h is 1. This works out the same no matter how small h is. When evaluating this limit, it makes no difference whether |h|/h is dened for h=0. All that matter is what happens when h is CLOSE TO 0. And for any value of h close to 0, |h|/h is 1. Thats the denition of college I have to takethis class which is about Math logic. Its going really fast for me and theother math phoebes. I have been to a hundred web sites and none of them havehelped. I need to know the following:1.What the hell dose the Q and the P stand for? true and false?2. How do you read a truth table?3. How do Ifind the principle of inference?4. Principle of a syllogism?And on and on.If I dont pass I dont graduate a Math disability and to graduate college I have to take> this class which is about Math logic. Its going really fast for me and the> other math phoebes. I have been to a hundred web sites and none of them have> helped. I need to know the following:1.What the hell dose the Q and the P stand for? true and false?Some context would have been nice but Ill take a guess.I suspect that P and Q or more likely, p and q stand for staements.Informally a statement is a sentence that can be either true or false.P := My cat is black is a statement. Q := Get lost. is not.> 2. How do you read a truth table?A truth table is a way of determining the truth values of a compoundstatement involving P and Q (and may even a third statement R) likenot(P and Q).The top row will have P, Q ,P and Q and not(P and Q). In thecolumns headed by P and Q, you put all possible truth values of P andQ:P QT TT FF TF F.The second row (actually the third but the top one doesnt count) saysP is true and Q is false. So, to complete the second row, you willconsult your and truth table and discover that when P is true (T) andQ is false (F), P and Q is false so youll put F in the second row ofthe P and Q column. Now, youll consult your not truth table anddiscover that when P and Q is false (F), not(P and Q) is true (T).So the whole second row of the table is: T F F T. That is, when P istrue and Q is false, not(P and Q) is true.An aside: your not table will probably have a column labeled P._That_ P is _your_ P and Q.If P:= 2 + 3 = 5 and Q := All cats have 10 lives then not(P and Q)is true.> 3. How do Ifind the principle of inference?Ive no idea. I need some context, example, something. > 4. Principle of a syllogism?Ditto.One doesnt, as a rule,find principles so I dont know what the lasttwo questions are.-- Paul and to graduate college I have to take>this class which is about Math logic. Its going really fast for me and the>other math phoebes.>I have been to a hundred web sites and none of them have>helped. Statements like this always trigger my b---s--- detector.>I need to know the following:1.What the hell dose the Q and the P stand for? true and false?>2. How do you read a truth table?>3. How do Ifind the principle of inference?>4. Principle of a syllogism?These are all answered in your textbook, and at much greater length than we could write out in a newsgroup. If the textbook doesnt help you, how can we? I dont understand any of it may be your honest feeling but it gives us nothing to work with, no way to know how to help you.If you can ask specic questions, we can provide specic answers. If you show evidence that you have actually tried to understand the material, well be more eager to.-- Stan Brown, Oak Road Systems, Cortland County, New York, USA http://OakRoadSystems.comFortunately, I live in the United States of America, where we aregradually coming to understand that nothing we do is ever ourfault, especially if it is but it probably wont be satisfyingto many of you though its greatly satisfying to me, as the problemIve highlighted is rather easy to demonstrate, and is a problem with*actual* decomposition of algebraic integers.Many of you may have considered decomposition of algebraic integers inthe abstract, but if youd dug into it, you might have made mathhistory.Consider the polynomial y^3 + 12y - 65which of course has 3 roots and is irreducible over Q. Now imagine dividing off all factors of 5 from its roots and gettingthe polynomial for which the results are roots.Give that polynomial.It turns out that you cant as theres a problem with decomposingalgebraic integers in actuality.What I can do is start you out on the polynomial as you have x^3 + sx^2 + tx - 13 and what neither you, nor any other mortal in all of the Universe cando is give s, and t, to *see* the polynomial.Not even I can even though I know that only two of the roots of y^3 + 12y - 65have a factor that is sqrt(5), but you see, you cant pick them out!You can prove that only two have that factor but because of thecuberoot operator, which must be used to display them, you have afundamental ambiguity, like how sqrt(1) = +/- 1, which prevents youfrom picking out which ones.So you cant calculate, and neither can you display s or t.They are fundamentally unknowable, which is a fascinating result.Dont believe me? Well then, gofind s and t.James wont be satisfying>to many of you though its greatly satisfying to me, as the problem>Ive highlighted is rather easy to demonstrate, and is a problem with>*actual* decomposition of algebraic integers.The sort of decompisition you have in mind _seems_ to be somethinglike a unique prime factorization. Its actually well-known that thereis no such thing in the algebraic integers - many of your mistakesarise from assuming that there is such a thing even though thereisnt (see below). This is not a problem with the algebraic integers,its a problem with your understanding of them.>Many of you may have considered decomposition of algebraic integers in>the abstract, but if youd dug into it, you might have made math>history.Just like youve made history. Right. >Consider the polynomial y^3 + 12y - 65which of course has 3 roots and is irreducible over Q. Now imagine dividing off all factors of 5 from its roots and getting>the polynomial for which the results are roots.There are at least two things you might mean by this:(i) take each root and divide by 5 as many times aspossible (while remaining within the algebraic integers),(ii) take each root and divide out all the factors (in thealgebraic integers) that it shares with 5. In other words,divide each root r by GCD(r, 5), where GCD meansgreatest common divisor in the algebraic integers.You might note that I think that (i) is the most naturalactually mean is (ii). But lets not worry about that -whichever one you meant, theres nothing historic here:Case 1: Assuming you meant (i): Then the thingsyou say below we cannot do are very easy, becauseits easy to see that none of the roots are divisibleby 5: If r is a root then r/5 is a root of 25y^3 + 12y - 13,hence r is not an algebraic integer. So after doing (i)the roots are unchanged, and the polynomial yousay we cant nd is just y^3 + 12y - 65.Case 2: Assuming you mean (ii): Asking us to divide out all the factors of 5 in the sense of(ii) simply doesnt make any sense. Someonecorrect me if Im wrong: There simply _is_no GCD in the algebraic integers!(If there _were_ a unique prime factorization in thealgebraic integers this would make sense.)>Give that polynomial.It turns out that you cant as theres a problem with decomposing>algebraic integers in actuality.What I can do is start you out on the polynomial as you have x^3 + sx^2 + tx - 13 and what neither you, nor any other mortal in all of the Universe can>do is give s, and t, to *see* the polynomial.Not even I can No. Surely _you_ can?>even though I know that only two of the roots of y^3 + 12y - 65have a factor that is sqrt(5),Its amazing how you repeat the same errors over and over.Youve never explained _why_ any of the roots have factorsof sqrt(5), and you ignore repeated very simple proofs that_none_ of them do!Well, since I havent been following the details maybe thisis a new one, and nobodys yet showed you a simple proofthat youre wrong. Its incredibly simple, so simple evenI can do it: Say r is a root of y^3 + 12y - 65. Then r/sqrt(5)is easily seen to be a root of 25x^6 + 120x^4 + 144x^2 - 845.Since thus polynomial is irreducible (or so Mathematica claims)it follows that r/sqrt(5) is not an algebraic integer.So there you are. _None_ of the roots have sqrt(5) as afactor (in the algebraic integers). And this is not hard tosee, its only a tiny bit more complicated than seeing thatnone of the roots have 5 as a factor.HINT: when you mistakes are so basic that its trivialfor a guy like me to demonstrate the error, even thoughI really dont know anything about these things, itfollows that youre making really basic mistakes.Over and over. And over.> but you see, you cant pick them out!Yeah. Just like you cant pick out the unicornhiding among all the other animals at the zoo.(_Some_ people _can_ see the unicorn. Theyrenot ordinary mortals. Of course above you implythat youre not an ordinary mortal either. Hmm.)>You can prove that only two have that factor but because of the>cuberoot operator, which must be used to display them, you have a>fundamental ambiguity, like how sqrt(1) = +/- 1, which prevents you>from picking out which ones.So you cant calculate, and neither can you display s or t.They are fundamentally unknowable, which is a fascinating result.Dont believe me? Well then, gofind s and t.>James because of the> cuberoot operator, which must be used to display them,You do not need the cube root operator to display such numbers.For example, if you use the ordered pairs of real numbers (r,s)to represent the complex numbers in the standard way, thenthe two square roots of -1 are (0, 1) and (0, -1). I dontneed the square root operator.> you have a> fundamental ambiguity, like how sqrt(1) = +/- 1, which prevents you> from picking out which ones.There is no ambiguity for sqrt(1) = +/- 1 since x^2 - 1 is not irreducible.Even for the cube root operator, there is no ambiguity in displayingsuch numbers. The ambiguity that you are referring to is the following.You say you are thinking of one of the cube roots and you want meto tell you which one you are thinking of. Of course, I cant dothat. But, that does not mean that I cant write down the threecube roots (in a given representation of the number system)unambiguously.Mine point is the following. You need to have already establishedthe existence of the numbers that you are discussing. Therecant be any ambiguity here. After having established theexistence of these numbers, then you can start talking aboutsome of them be roots of a particular irreducible cubicpolynomial. Those three roots will be distinguishable inthe pre-existing established number system.-- Bill unicorn> hiding among all the other animals at the zoo.--There are two things you must never attempt to prove: the unprovable -- andthe obvious.--Democracy: The triumph of popularity over resolution, but it probably wont be satisfyingto James as it mean (ii): Asking us to |divide out all the factors of 5 in the sense of|(ii) simply doesnt make any sense. Someone|correct me if Im wrong: There simply _is_|no GCD in the algebraic integers!||(If there _were_ a unique prime factorization in the|algebraic integers this would make sense.)i wouldnt swear im not screwing up here, but the impression i haveis that the algebraic integers have a good concept of gcd _despite_lacking unique prime factorization. that is, arturo magidin mentionedin a post on april 13 that the algebraic integers form a bezoutdomain, which is a kind of ring in which (if i understand correctly)the sum of any two principal ideals is principal. the operation ofsum of principal ideals corresponds to the operation of gcd of ringelements, so a bezout domain has a good concept of gcd.-- satisfying> to many of you though its greatly satisfying to me, as the problem> Ive highlighted is rather easy to demonstrate, and is a problem with> *actual* decomposition of algebraic integers.Many of you may have considered decomposition of algebraic integers in> the abstract, but if youd dug into it, you might have made math> history.Consider the polynomial y^3 + 12y - 65which of course has 3 roots and is irreducible over Q. Now imagine dividing off all factors of 5 from its roots and getting> the polynomial for which the results are roots.Give that polynomial.It turns out that you cant as theres a problem with decomposing> algebraic integers in actuality.What I can do is start you out on the polynomial as you have x^3 + sx^2 + tx - 13 and what neither you, nor any other mortal in all of the Universe can> do is give s, and t, to *see* the polynomial.Damn. Um, I think you can give them. Oh well, back to the drawing board.James wont be satisfying> to many of you though its greatly satisfying to me, as the problem> Ive highlighted is rather easy to demonstrate, and is a problem with> *actual* decomposition of algebraic integers.Many of you may have considered decomposition of algebraic integers in> the abstract, but if youd dug into it, you might have made math> history.Consider the polynomial y^3 + 12y - 65which of course has 3 roots and is irreducible over Q. Now imagine dividing off all factors of 5 from its roots and getting> the polynomial for which the results are roots.Give that polynomial.It turns out that you cant as theres a problem with decomposing> algebraic integers in actuality.> I concede it is difcult to do the computation (though not impossible). But the real question here is: so what?Does the fact that it is difcult to write down such a polynomial prove that you are right in your claims, or prove that the rest of us are wrong? Isnt it just anirrelevant side issue?> What I can do is start you out on the polynomial as you have x^3 + sx^2 + tx - 13 and what neither you, nor any other mortal in all of the Universe can> do is give s, and t, to *see* the polynomial.Not even I can even though I know that only two of the roots of y^3 + 12y - 65have a factor that is sqrt(5), but you see, you cant pick them out!>Let y be any root of [1] y^3 + 12y - 65 = 0.Substitute y = x + 5. Then [1] is equivalent to x^3 + 15*x^2 + 75*x = -120, or[2] x*(x^2 + 15*x + 75) = -120.Now suppose x is coprime to 5.Then clearly x^2 + 15*x + 75 is also coprime to 5.Therefore in [2], both x and (x^2 + 15*x + 75)are coprime to 5. The right side, however, is120, which is not coprime to 5. There is a theorem which says: If A and B are algebraic integers which are coprime to p, then both A and B are coprime to p. [see proof below {***}]Therefore a contradiction. Therefore x is NOTcoprime to 5. But y = x + 5.Therefore y is also not coprime to 5.Therefore ALL roots of [1] are not coprimeto 5.Therefore your statement that exactly two ofthe roots are divisible by sqrt(5) (and thus that the other one is necessarily coprime to 5) is wrong.{***} Proof of theorem: Assume A is coprime to p and B is coprime to p. Then there exist algebraic integers r and s, and r and s such that r*A + s*p = 1 and r*B + s*p = 1. Therefore r*A*B + s*p*B = B. Therefore r*(r*A*B + s*p*B) + s*p = 1 This can be rearranged as: r*r*(A*B) + (r*s*B + s)*p = 1, which implies that A*B and p are coprime. QED.Nora B. [more irrelevant stuff message,corrected below at {###}.Nora B.> Well nally theres resolution, but it probably wont be satisfying> to many of you though its greatly satisfying to me, as the problem> Ive highlighted is rather easy to demonstrate, and is a problem with> *actual* decomposition of algebraic integers.Many of you may have considered decomposition of algebraic integers in> the abstract, but if youd dug into it, you might have made math> history.Consider the polynomial y^3 + 12y - 65which of course has 3 roots and is irreducible over Q. Now imagine dividing off all factors of 5 from its roots and getting> the polynomial for which the results are roots.Give that polynomial.It turns out that you cant as theres a problem with decomposing> algebraic integers in actuality.> I concede it is difcult to do the computation (though not impossible). But the real question here is: SO WHAT?Does the fact that it is difcult to write down such apolynomial prove that you are right in your claims, orprove that the rest of us are wrong? Isnt it just anirrelevant side issue?> What I can do is start you out on the polynomial as you have x^3 + sx^2 + tx - 13 and what neither you, nor any other mortal in all of the Universe can> do is give s, and t, to *see* the polynomial.Not even I can even though I know that only two of the roots of y^3 + 12y - 65have a factor that is sqrt(5), but you see, you cant pick them out!> Let y be any root of [1] y^3 + 12y - 65 = 0. Substitute y = x + 5. Then [1] is equivalent to x^3 + 15*x^2 + 75*x = -120, or[2] x*(x^2 + 15*x + 75) = -120.Now suppose x is coprime to 5. Then clearly x^2 + 15*x + 75 is also coprime to 5.Therefore in [2], both x and (x^2 + 15*x + 75)are coprime to 5. The right side, however, is-120, which is not coprime to 5. There is a theorem which says: If A and B are algebraic integers which{###} are coprime to p, then A * B is coprime <--Misstatement was here> to p. [See proof below.]Therefore a contradiction. Therefore x is NOTcoprime to 5.But y = x + 5.Therefore y is also not coprime to 5.Therefore ALL roots of [1] are not coprimeto 5.Therefore your statement that exactly two ofthe roots are divisible by sqrt(5) (and thus thatthe other one is necessarily coprime to 5) is wrong.{***} Proof of theorem: Assume A is coprime to p and B is coprime to p. Then there exist algebraic integers r and s, and r and s, such that r*A + s*p = 1 and r*b + s*p = 1. Therefore (multiplying the rst equality by B), r*A*B + s*p*B = B. Therefore (using the second equality) r*(r*A*B + s*p*B) + s*p = 1. This can be rearranged as r*r*(A*B) + (r*s*B + s)*p = 1, which implies that A*B and p are coprime. QED.Nora B.[more this post were just plainwrong due to an algebraic error. Note however that David Ullrich has given a simple valid disproof of Harriss statement that two of the roots of y^3 + 12*y - 65are divisible by sqrt(5). Nora B.> Well nally theres resolution, but it probably wont be satisfying> to many of you though its greatly satisfying to me, as the problem> Ive highlighted is rather easy to demonstrate, and is a problem with> *actual* decomposition of algebraic integers.Many of you may have considered decomposition of algebraic integers in> the abstract, but if youd dug into it, you might have made math> history.Consider the polynomial y^3 + 12y - 65which of course has 3 roots and is irreducible over Q. Now imagine dividing off all factors of 5 from its roots and getting> the polynomial for which the results are roots.Give that polynomial.It turns out that you cant as theres a problem with decomposing> algebraic integers in actuality.What I can do is start you out on the polynomial as you have x^3 + sx^2 + tx - 13 and what neither you, nor any other mortal in all of the Universe can> do is give s, and t, to *see* the polynomial.Not even I can even though I know that only two of the roots of y^3 + 12y - 65have a factor that is sqrt(5), but you see, you cant pick them out!You can prove that only two have that factor but because of the> cuberoot operator, which must be used to display them, you have a> fundamental ambiguity, like how sqrt(1) = +/- 1, which prevents you> from picking out which ones.So you cant calculate, and neither can you display s or t.They are fundamentally unknowable, which is a fascinating result.Dont believe me? Well then, gofind s and out all the factors (in the>algebraic integers) that it shares with 5. In other words,>divide each root r by GCD(r, 5), where GCD means>greatest common divisor in the algebraic integers. [.snip.]>Case 2: Assuming you mean (ii): Asking us to >divide out all the factors of 5 in the sense of>(ii) simply doesnt make any sense. Someone>correct me if Im wrong: There simply _is_>no GCD in the algebraic integers!(If there _were_ a unique prime factorization in the>algebraic integers this would make sense.)There is a natural way of dening a gcd, but it is not uniquelydetermined; it is only determined up to units. Since the algebraic integers are a Bezout domain (so every nitelygenerated ideal is principal), then given any two algebraic integers aand b, the ideal (a,b) is principal. Let c be any generator of(a,b). Then c satises the following two properties:(1) c|a and c|b;(2) if d is any algebraic integer such that d|a and d|b, then d|c.So it makes sense to call c ->a<- greatest common divisor of a and b,and it is unique up to reasoner as Mr. Smith? I answer as a deceased friend of mine used to answer on like occasions - A mans capacity is no measure of his power to do mischief. Mr. Smith has untiring energy, which does something; self-evident honesty of conviction, which does more; and a long purse, which does most of all. He has made at least ten publications, full of gures few readers can critize. A great many people are staggered to this extend, that they imagine there must be the indenite something in the mysterious all this. They are brought to the point of suspicion that the mathematicians ought not to treat all this with such undisguised contempt, at least. -- A Budget of Paradoxes, Vol. 2 p. 129 by Augustus de dont think this works...consider the group G/H = (Z_6 x> Z_4)/<(3,2)>. This group has order 12 and is generated by _(1,-1)_ => _(1,0)_ - _(0,1)_ (Im using underscoring to represent cosets of> <(3,2)> in Z_6 x Z_4.Then n = 12, x = 3, y = 2, so that would meanG/H = <_(1,0)_, _(0,1)_ | 4_(1,0)_ = _(0,0)_ and 2_(1,0)_ => 3_(0,1)_>.But 4_(1,0)_ = _(0,0)_ is false....doh.Maybe Im misunderstanding your original qustion.Suppose we have a cyclic group G of order n, generated by some element(g-h), and obeying the presentation (with g + h = h + g implicit):G = I thought you wanted values for a, b, c that would generate Z_n, andsuch that (g-h) is a generator.This does not imply that _every_ pair of elements g and h with(g-h) = (g - h) will satisfy ag = 0, cg = bh; its a statementthat, given that there exist elements g and h in G satisfying therelations, (g-h) will generate the group, which will be isomorphic toZ_n.In your example, let g = 3*_(1,-1)_ = _(3,-3)_; and let h = 2*_(1,-1)_= _(2,-2)_. Clearly, 4*g = 12*_(1,-1)_ = _(0,0)_; and 2*g = 6*_(1,-1)_= 3*h; and g-h = _(1,-1)_, which as you note generates the group.If you have _already selected_ g and h from G cyclic of order n, withthe property that G = <(g-h)>, can we always get a goodpresentation?Let k = (g-h). Then since G = , for some x, g = xk; and for y =x-1, h = yk.Then the order of g is a = lcm(n,x)/x, and r = lcm(n,y)/y is the orderof h. Then yg = yxk = xyk = xh. Let c = y mod a, and b = x mod r; thencg = bh. Assuming c and b are coprime (I think they always are, cantprove it off the top of my head, but I think it follows from x coprimeto y), then g and h satisfy the presentation:G = and G is isomorphic to Z_n.In your example, k = _(1,-1)_. g = _(1,0)_ = {(4,2), (1,0)}; it hasorder a = 6, and g = 10*k = _(10,-10)_ = _(4,2)_ = _(1,0)_. h =_(0,-1)_ has order r = 4, and h = 9*k = _(9,-9)_ = _(3,-1)_ = _(3,3)_= _(1,0)_. 9g = 10h, so 3g = 2h.SoG = (3g - 2h) - h = 3g - 3h = 3(g-h) = -h(3g - 2h) - g = 2g - 2h = 2(g-h) = -ggiving us (as we hoped and expected!)g = 10(g-h)h = 9(g-h)and so the group is cyclically generated by (g-h). p_k^r_k; and let x and y be integers > 1 such that xy = prod(p_i) for> i = 1 to k and, WLOG, x > y. Then (x - y) will not be divisible by> p_i for any i; and thus (x-y) will be coprime to n, and generate Z_n.Let a = n/x, b = y, c = x. Then should give a> <(3,2)> = {(3,2),(0,0)}> <_(1,-1)_> = <_(1,3)_ = {_(1,3)_, _(2,2)_, _(3,1)_, _(4,0)_, _(5,3)_, _(0,2)_,> _(1,1)_, _(2,0)_, _(3,3)_, _(4,2)_, _(5,1)_, _(0,0)_}_(2,0)_ = 2_(1,0)_ = 3_(0,1)_ = _(0,3)_ ??? ^^^ |||Why do you think this? _(3,3)_ = _(0,3)_ Perhaps you meant:_(3,0)_ = { (3,2) + (3,0), (0,0) + (3,0)} = ( (0,2), (3,0) } = ( (0,2) + (0,0), (0,2) + (3,2)} = _(0,2)_> _(0,0)_ = _(2,0)_ - _(0,3)_ = _(2,-3)_ = _(2,1)_ ???> _(0,0)_ = _(3,0)_ - _(0,2)_ = _(3,-2)_ = _(3,2)_ = _(0,0)_ reply to a line of yours below.> What does this line _(0,0)_ = _(2,0)_ - _(0,3)_ = _(2,-3)_ = _(2,1)_ ??? intend to show?> <(3,2)> = {(3,2),(0,0)}> <_(1,-1)_> = <_(1,3)_ > = {_(1,3)_, _(2,2)_, _(3,1)_, _(4,0)_, _(5,3)_, _(0,2)_,> _(1,1)_, _(2,0)_, _(3,3)_, _(4,2)_, _(5,1)_, _(0,0)_}> > _(2,0)_ = 2_(1,0)_ = 3_(0,1)_ = _(0,3)_ ???> _(0,0)_ = _(2,0)_ - _(0,3)_ = _(2,-3)_ = _(2,1)_ ???> > As you top post, I presume you want me to top post also.> > I dont think this works...consider the group G/H = (Z_6 x> Z_4)/<(3,2)>. This group has order 12 and is generated by _(1,-1)_ => _(1,0)_ - _(0,1)_ (Im using underscoring to represent cosets of> <(3,2)> in Z_6 x Z_4.> > Then n = 12, x = 3, y = 2, so that would mean> > G/H = <_(1,0)_, _(0,1)_ | 4_(1,0)_ = _(0,0)_ and 2_(1,0)_ => 3_(0,1)_>.> > But 4_(1,0)_ = _(0,0)_ is false....doh.> > Heather did.> <(3,2)> = {(3,2),(0,0)}> <_(1,-1)_> = <_(1,3)_ > = {_(1,3)_, _(2,2)_, _(3,1)_, _(4,0)_, _(5,3)_, _(0,2)_,> _(1,1)_, _(2,0)_, _(3,3)_, _(4,2)_, _(5,1)_, _(0,0)_}> > _(2,0)_ = 2_(1,0)_ = 3_(0,1)_ = _(0,3)_ ???> ^^^> |||> Why do you think this? _(3,3)_ = _(0,3)_ Perhaps you meant: _(3,0)_ = { (3,2) + (3,0), (0,0) + (3,0)}> = ( (0,2), (3,0) }> = ( (0,2) + (0,0), (0,2) + (3,2)}> = _(0,2)_ > _(0,0)_ = _(2,0)_ - _(0,3)_ = _(2,-3)_ = _(2,1)_ ???_(0,0)_ = _(3,0)_ - _(0,2)_ = <_(1,-1)_> = <_(1,3)_ > = {_(1,3)_, _(2,2)_, _(3,1)_, _(4,0)_, _(5,3)_, _(0,2)_,> _(1,1)_, _(2,0)_, _(3,3)_, _(4,2)_, _(5,1)_, _(0,0)_}> > _(2,0)_ = 2_(1,0)_ = 3_(0,1)_ = _(0,3)_ ???> ^^^> |||> Why do you think this? _(3,3)_ = _(0,3)_> I dont, prime decomposition of n be n = p_1^r_1 p_2^r_2 ...> p_k^r_k; and let x and y be integers > 1 such that xy = prod(p_i) for> i = 1 to k and, WLOG, x > y. Then (x - y) will not be divisible by> p_i for any i; and thus (x-y) will be coprime to n, and generate Z_n.Let a = n/x, b = y, c = x. Then should give a> presentation (assuming g+h = h+g) of Z_n - I think!!> I think you want > a = n/y, b = y, c = x.In my example, this gives a = 12/2 = 6, and indeed 6*_(1,0)_ x*g=y*h>.Can you get a symmetric condition in terms of the order of h? At rstglance it would look like ord(h)=n/x, but in our example, this wouldmeanord(_(0,1)_)=12/3=4.We need 4*_(0,1)_ = _(0,0)_.==> 4*[ (0,1) + <(3,2)> ] = <(3,2)>==> 4<(3,2)>=<(3,2)>==> (12,8)=(3,2) .... False.> For any n, let the prime decomposition of n be n = p_1^r_1 p_2^r_2 ...> p_k^r_k; and let x and y be integers > 1 such that xy = prod(p_i) for> i = 1 to k and, WLOG, x > y. Then (x - y) will not be divisible by> p_i for any i; and thus (x-y) will be coprime to n, and generate Z_n.Let a = n/x, b = y, c = x. Then should give a> presentation (assuming g+h = h+g) of Z_n - I think!!> I think you want a = n/y, b = y, c = x.In my example, this gives a = 12/2 = 6, and indeed with predicate logic as the highestnode on the tree what other disciplines would be under that tree? Also aretheir any disciplines that are of a higher priority then Predicate logic?Explain. If you have any web resources to illustrate the tree structure with predicate logic as the highest> node on the tree what other disciplines would be under that tree? Also are> their any disciplines that are of a higher priority then