Equidimensional Part

Calculate the equidimensional part of a variety via Ext-groups.

The equidimensional part of V={xz=yz=0} is given by the ideal:

(z)=ann(Ext¹(K[x,y,z]/(xz,yz),K[x,y,z]))

LIB "homolog.lib";
ring r=0,(x,y,z),dp;
ideal i=xz,yz;
module m=Ext_R(1,i);
quotient(m,freemodule(nrows(m)));
=> _[1]=z