nzd

Usage:
    <nzd x m mbar
Test to see whether the linear form x is a nonzerodivisor
on m and set mbar = m/xm OVER THE CURRENT RING
( if the base ring of m has n variables, the first
n-1 variables of the current ring are used )
Parameters:
            x = 1x1 matrix containing a linear form
            m = module
Output values:
            mbar = m/xm as a module over the current ring
    The program also prints a message telling whether
            x is a nonzerodivisor on m.
The program uses the saturation method for finding whether
x is a nonzerodivisor -- generally cheapest, as it involves only
one standard basis computation, and that in reverse lex order.
The ideal that is printed is actually (0:x*)_m, the set of all
elements of m which are killed by a power of x.