D.4.28.1 Ann

Usage:

Ann(M); M module

Return:

ideal, the annihilator of coker(M)

Note:

The output is the ideal of all elements a of the basering R such that a * R^m is contained in M (m=number of rows of M).

LIB "primdec.lib";
ring  r = 0,(x,y,z),lp;
module M = x2-y2,z3;
Ann(M);
==> _[1]=z3
==> _[2]=x2-y2
M = [1,x2],[y,x];
Ann(M);
==> _[1]=x2y-x
qring Q=std(xy-1);
module M=imap(r,M);
Ann(M);
==> _[1]=0