Singular

D.6.9.2 coDim

Usage:

coDim(module M, module N, ideal I,int bound, list #); M is a submodule in A^r over the basering=:A, N is a submodule in R^r over the subring R of the basering generated by the entries of I

Compute:

computes the K-vectorspace dimension of A^r/M+N+maxideal(bound)*A^r

Return:

an integer

Note:

if # is not empty the bound is corrected by computing determinacy

LIB "classifyMapGerms.lib";
ring R=0,(x,y),(c,ds);
poly f1=x;
poly f2=xy+y5+y7;
poly f11=f1+f2*f1;
poly f22=f2+f1^2;
map phi=basering,x+y,y+y2;
f1=phi(f11);
f2=phi(f22);
ideal I=f1,f2;
module M=maxideal(1)*jacob(I);
module N=I*freemodule(2);
coDim(M,N,I,15);
==> 6