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Re: Problem with Expand and Modulus in Mathematica 9?
Posted:
Dec 29, 2012 3:08 PM


Hi there
Below the result for a MacPro  Darwin Kernel Version 12.2.0  64 bit  running Mathematica 9
1651432217+309632549 n+188919829 n^2+1597920481 n^3
Cheers
Ed
On Dec 28, 2012, at 8:37 AM, Ralf Hemmecke <hemmecke@gmail.com> wrote:
> Can someone confirm that the following code gives different results for r1 for different versions of Mathematica and different operating systems. Or is this just an issue of my installation? > > BEGIN CODE > m = 2147483629 > q = 285170499 > q1 = 1/q > q2 = PowerMod[q,1,m] > Mod[q*q2, m] > p1 = 527660967 + 978421595*n > p2 = 1999783961 + 1587123368*n + 1965760814*n^2 > r1 = Expand[q1*p1*p2,Modulus>m] > r2 = Expand[q2*p1*p2,Modulus>m] > s1 = Expand[Expand[q1*p1*p2],Modulus>m] > s2 = Expand[Expand[q2*p1*p2],Modulus>m] > END CODE > > Value of r1 > Mathematica 8 > 1808010833 + 1914426603*n + 640234431*n^2 + 1087084730*n^3 > > Mathematica 9 (64bit Debian 6.0) > 1651432217 + 309632549*n + 188919829*n^2 + 1597920481*n^3 > > Mathematica 9 (32bit Debian 6.0, 64bit CPU) > 1823075307 + 33175446*n + 2081129601*n^2 + 580053941*n^3 > > The values of r2, s1, s2 agree with that of r1 as computed in Mathematica 8. > > Ralf >



