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D.4.10.11 isCM

Procedure from library homolog.lib (see homolog_lib).

Usage:
isCM(M); M module

Return:
1 if M'=coker(M) is Cohen-Macaulay;
0 if this is not the case.

Assume:
basering is local.

Example:
 
LIB "homolog.lib";
ring R=0,(x,y,z),ds;  // local ring R = Q[x,y,z]_<x,y,z>
module M=xz,yz,z2;
isCM(M);             // test if R/<xz,yz,z2> is Cohen-Macaulay
==> 0
M=x2+y2,z7;          // test if R/<x2+y2,z7> is Cohen-Macaulay
isCM(M);
==> 1