D.4.17.8 modregCM

Usage:

modregCM(i); i ideal

Return:

an integer, the Castelnuovo-Mumford regularity of i.
(returns -1 if i is not homogeneous)

Assume:

i is a homogeneous ideal and the characteristic of base field is zero..

Note:

This is a probabilistic procedure, and it computes the initial of the ideal modulo the prime number 2147483647 (the biggest prime less than 2^31).