D.5.18.3 CM_regularity

Usage:

CM_regularity(M); M module

Assume:

M is graded, and it comes assigned with an admissible degree vector as an attribute

Return:

integer, the Castelnuovo-Mumford regularity of coker(M)

Note:

procedure calls mres

LIB "sheafcoh.lib";
ring R=0,(x,y,z,u),dp;
resolution T1=mres(maxideal(1),0);
module M=T1[3];
intvec v=2,2,2,2,2,2;
attrib(M,"isHomog",v);
CM_regularity(M);
==> 2