Re: Working modulo 2

*To*: mathgroup at smc.vnet.net*Subject*: [mg92120] Re: Working modulo 2*From*: Peter Pein <petsie at dordos.net>*Date*: Sat, 20 Sep 2008 05:01:27 -0400 (EDT)*References*: <gavt0g$g4u$1@smc.vnet.net>

me13013 schrieb: > Howdy, > > How does one reduce a polynomial's coefficients modulo 2? For > example, I have a function that sums several polynomials, and > currently produces a result like this: > 7 + x + 4 y + 4 x y + 3 z + 2 x z + 4 y z + 4 x y z > I want to reduce this to > 1 + x + z > > I thought I might be able to do this by somehow coercing the terms > into a list and then doing Sum[L[[i]],{i,1,Length[L]},Modulus->2], but > no such luck. > > Any ideas? > > Thanks, > Bob H > Hi Bob, ReplaceAll is what you need: 7+x+4 y+4 x y+3 z+2 x z+4 y z+4 x y /.i_Integer:>Mod[i,2] 1+x+z Peter