mm-39 === Be unhappy all you want, I don't care for your nitpicking Maple bugreports. Why don't you submit some code to solve these bugs, eh?If you search the archives of Basti's postings from a year ago, you willfind he made statements like : I am the leader of modern mathematics...Nobody but a crank makes statements like these - I rest my case.Caesar Garcia> Dear Caesar Garcia,While I have not read these papers yet, and, thus, have none > idea on account of if Dr Basti is right or wrong there, I must> admit that I am feeling fairly unhappy with the way you were> expressing your opinion this time.I'd say, I am hearing strong malevolence in your voice.> AFAIK, torrent of emotion tends to break human reasoning.Publishing or not publishing a paper not necessarily means> the paper is wrong; for example, it simply can be written in> a difficult to read fashion etc. As you most probably know,> the ultimate example of publishers' blunder is Galois' papers:> nobody published them over decades.http://www.galois-group.net/I was wondering have you read all Dr Basti's papers yourself?> If not which seems to be the case, then - no comment.CG> I wonder if your new employers would have been so keen > CG> to hire you if they knew you were such a nutcase.I am certain that if I would ever hire a person like you I > would fall into a serious error as such a person is obviously > not a team player and would make constant attempts to break> communication within the company. Speaking so I do not mean that you are a bad or good > person, IMHO, such statements are of no use; I also have> none idea what talents you are endowed by. I just mean you> looks like an individual player; there are and certainly> there will be always individual players of superlative power,> for example, a Nobel prize winner Frederick Soddy who once> worked with Ernest Rutherfordhttp://www.nobel.se/chemistry/laureates/1921/ soddy-bio.html> Could I kindly ask you to report us rather more facts about > Dr Basti's papers? I am very interested in hearing from you> on this and other points.Best wishes,Vladimir BondarenkoCo-founder, CEO, Mathematical Director> Cyber Tester, LLChttp://www.cybertester.com/................................ ............................. === >>> So the strategy I am using is to implement a user friendly syntax for>> metamathematics plus axiomatic set theory. But I doubt it will hold for>> any serious proof verification system. So on top of that, I may add a>> system for user defined syntax. Then this may in fact be asimplification>> for further implementations.>>A very ambitious project. Good luck!>> It is not as ambitious as it may sound, as I decided to not work with> optimizations. But I have implemented things like unification branching in> order to achieve an proof-engine that is as general as possible. This way> I do not need Gentzen sequents, it seems.>> One idea that comes to my mind is that you might look at using the> semantic trees to write an interface on top of a program like Qu-Prolog.> This might saving you some time. :-)>Save me some time? As the subject heading indicates, I have alreadyimplemented my system. If you haven't already done so, please have a look atit and let me know what you think. (System requirements: Windows 95 orlater, and IE4 or later.) Try out the tutorial (click the Help button) toget a general idea of the system's capabilities. Examples in the tutorialinclude Russell's Paradox and what I called the Paradox of the UniversalSet.DanVisit DC Proof Online at http://www.dcproof.com -- FREE download === I posted this in another group. But I wanted to get some feedbacksfrom you guys as well.I was wondering. what are some criteria mathematicians use in order tofigure out if there is (an) anlytical solution(s) to a given ode orode system?if there are many, then what books are available that shows suchmethods?what can you suggest? any thoughts are welcome. thanks in advancejohn === See for example the list of references here:http://lie.uwaterloo.ca/odetools/references.htmlI posted this in another group. But I wanted to get some feedbacks> from you guys as well.I was wondering. what are some criteria mathematicians use in order to> figure out if there is (an) anlytical solution(s) to a given ode or> ode system?if there are many, then what books are available that shows such> methods?what can you suggest? any thoughts are welcome. thanks in advancejohn === 1. Given two arbitary symbolic expressions involving only real algebraicnumbers of constant value (e.g. 1/6, Sqrt(37/6) are simple examples), is itpossible to determine computationally if one expression is less than orequal to the other? (Presumably this is at least as hard as the zeroequivalence problem?).2. If it is possible, is it well-understood and computationally tractible?3. If 2., then is it also the sort of thing that one might reasonably expecta computer algebra package to handle?TIA,James. === Download beta 1 - www.master-graph.com/mgraph20b1.exe (only 477KB).All who will help me to improve this program will get a freeregistration key.You can do the following:-find bugs-feedback about you impression by the program-advice me to change or add some new features-translate it to the other language (seewww.master-graph.com/instructions/interface.html)Feel free to contact with me - roman@master-graph.comSincerely,Roman. === Hoops 1-4 developed Hoop division algebras, collapsed from Moufangloops with r-fold symmetry and having additive elimination asgeneralized subtraction. Sizes are functions that are conserved onhoop multiplication; the sizes of a product are the products of thecorresponding sizes of the multiplicands. I now explore theconsequences of sizes becoming zero.(5a) Sizes can become zero. New possibilities exist in non-degenerate algebras that conservemore than one size. Sizes of vecs (generalized vectors) can becomezero without the vec becoming a null vec. C3 conserves a+b+c and((a-b)^2+ (b-c)^2+ (c-a)^2)/2 and so the zeroes occur when eithera+b=-c or a=b=c. D3 conserves a+b+c+d+e+f, a-b+c-d+e-f, & ((a-b)^2+(b-c)^2+ (c-a)^2 -(d-e)^2- (e-f)^2- (f-d)^2)/2, and so has 3non-trivial zeroes. (5b) Zero sizes constrain calculations to a sub-algebra. A multiplicand with a zero size gives a product with the same sizeequal to zero. The result is projected onto a sub-algebra (to whichthe multiplicand belongs) in which this size is constrained to zero.The sub-algebra has lost a symmetry. (5c) Operations with a zero size renormalize. Division by a vector in the constrained algebra propagates the sameconstraint. This is effected by the genInverse function; partialfractions are ignored if the denominator is less than some prescribedh (i.e. if the size approximates to zero). Conic sections provide ananalogy. The bi-cone is highly 3D symmetrical. Restrictingconsideration to a 2D plane gives various less symmetrical 2D figures.The system is constrained to have zero distance from the plane. This corresponds to renormalization, the meta-mathematical trickused by mathematical physicists to dispose of un-physical infinities.It also corresponds to sub- & super-symmetry and the use of gradedalgebras. Roger Beresford.Now you see it. Now you don't! (Magician's patter.) === In the program Mathematica, one can factor an equation Modulus a Primenumber. However, I am having a hard time trying to understand how tointerpret the output. Could someone offer a simple explanation ofFor example, the following normally cannot be factored any further.Factor[5 + x^2]5 + x^2However, if we factor this using the option Modulus a Prime number, we geta different output.Factor[5 + x^2, Modulus -> 3](1 + x)*(2 + x)..or2 + 3*x + x^2I have been having a hard time understanding just what the output is tryingto tell me.I understand how Mod[7, 3] returns 1, but I do not see the relationship-- Dana === > In the program Mathematica, one can factor an equation Modulus a Prime> number. However, I am having a hard time trying to understand how to> interpret the output. Could someone offer a simple explanation of> For example, the following normally cannot be factored any further.> Factor[5 + x^2]5 + x^2However, if we factor this using the option Modulus a Prime number, we get> a different output.> Factor[5 + x^2, Modulus -> 3](1 + x)*(2 + x)> ..or> 2 + 3*x + x^2I have been having a hard time understanding just what the output is trying> to tell me.> I understand how Mod[7, 3] returns 1, but I do not see the relationshipCalculating mod 3, Mathematica maps..., -6,-3,0,3,6,9, .... to 0..., -5,-2,1,4,7,10, ... to 1..., -4,-1,2,5,8,11, ... to 2so you asked for the factors of x^2+2, when reduced mod 3.It gave you the factors 1+x and 2+x.multiplied together gives 2+3x+x^2, but note that 3 is the same as 0.so the result is 2+x^2. That's what you asked to factor.> X-Received: (from approve@localhost) by support1.mathforum.org (8.11.6/8.11.6/The Math Forum, $Revision: 1.9 primary) id i09NO2k28322; === I am trying to solve PDEs in the following manner: setup the PDEsin Maple (v.9), generate a C code of the corresponding set of ODEs,mex them to make a .dll file and use MATLABs ODE45() to solve thesystem of ODEs. I have tested an example problem successfully consisting of 3ODEs. Here is the Maple code for that.//// Start Code /////> restart;> with(CodeGeneration):Warning, the protected name Matlab has been redefined and unprotected> with(DEtools,convertsys):> Lorenz := [ diff(x(t),t) = 1.0*(y(t)-x(t)),> diff(y(t),t) = 1.0*x(t)-y(t)-x(t)*z(t),> diff(z(t),t) = x(t)*y(t)-1.0*z(t) ]:> init := x(0)=1.0, y(0)=1.0, z(0)=1.0; init := x(0) = 1.0, y(0) = 1.0, z(0) = 1.0> S := convertsys( Lorenz, [init], [x(t),y(t),z(t)], t, y, yp );S := [[yp[1] = 1.0 y[2] - 1.0 y[1], yp[2] = 1.0 y[1] - y[2] - y[1]y[3], yp[3] = y[1] y[2] - 1.0 y[3]], [y[1] = x(t), y[2] = y(t), y[3] =z(t)], 0, [1.0, 1.0, 1.0]]> yp := array(map(rhs,S[1]));yp := [1.0 y[2] - 1.0 y[1], 1.0 y[1] - y[2] - y[1] y[3], y[1] y[2] -1.0 y[3]]> example_3ode := codegen[makeproc](yp, parameters=[yp,t,y]);example_3ode := proc(yp::array(1 .. 3), t, y) yp[1] := 1.0*y[2] - 1.0*y[1]; yp[2] := 1.0*y[1] - y[2] - y[1]*y[3];yp[3] := y[1]*y[2] - 1.0*y[3]; return ;end proc;> C(example_3ode,output=example_3ode.c);//// End Code ////I could mex the output file example_3ode.c and make it a .dll fileusing a mexFunction and solve the ODEs using ODE45() of MATLAB.I have also considered a sample PDE problem, x(r,t). I converted thePDE into a set of ODEs. But I have not been able to convert the systemof ODEs as done in the above case. I am providing the correspondingcode below. Can somebody please take a look at it and let me know howto go about the problem.//// Start Code ////> restart;> read`D:/madhu/FuelCells/PEMFCModeling/ModelingUsingMaple9/pde/ fdpack.mpl`:> read`D:/madhu/FuelCells/PEMFCModeling/ModelingUsingMaple9/ utils/utils.mpl`:> read`D:/madhu/FuelCells/PEMFCModeling/ModelingUsingMaple9/ plots/plots.mpl`:> read `D:/madhu/FuelCells/PEMFCModeling/ModelingUsingMaple9/BESIRK`: > with(DEtools,convertsys):> PDE1 := diff(x(r,t),t) = nu*diff(x(r,t),r): PDE1;> IC1 := t=0, x(r,t) = 0.0: IC1; t = 0, x(r, t) = 0.> BC1 := r=0, x(r,t) = 1.0: BC1; r = 0, x(r, t) = 1.0> BC2 := r=1.0, x(r,t) = 10.0: BC2; r = 1.0, x(r, t) = 10.0> n_x := 11; n_x := 11> rspec := h_r = 1.0/(n_x-1): rspec; h_r = 0.1000000000> PDE1a :=convert(PDE1,fddiff,order=[1,0],forward=[1,0],indexletters=[ j,none]):PDE1a; d nu (x[j + 1] - x[j]) -- x[j] = -------------------- dt h[r] > PDE1b := subs(r[j]=(j-1)*h[r],h[r]=h_r,PDE1a): PDE1b; d nu (x[j + 1] - x[j]) -- x[j] = -------------------- dt h_r > BC1a :=convert(BC1[2],fddiff,order=[2,0],forward=[2,0],indexletters =[1,none]):BC1a := subs(h[r]=h_r,BC1a): BC1a; x[1] = 1.0> BC2a :=convert(BC2[2],fddiff,order=[2,0],forward=[2,0],indexletters= [n_x,none]):BC2a := subs(h[r]=h_r,BC2a): BC2a; x[11] = 10.0> params := {nu=0.05}: params; {nu = 0.05}> xeqns := [seq(PDE1b,j=2..n_x-1)];> whattype(xeqns); list> S := convertsys(xeqns, [], [seq(x[j],j=2..n_x-1)], t, x, xp ):Error, (in DEtools/convertsys) invalid system of differentialequations//// End Code ////Not sure how do I go about the above error message.madhu