uminus
description:
g=uminus(f) is called for the syntax '-f' and means symbolic negation.
arguments:
NCpoly representing the polynomial f or matrix of NCpolys
output:
NCpoly representing the polynomial -f
possible usage:
-f, uminus(f)
example:
>> f=[x^2-2*x*y, (x-y)^2];
>> -f
ans = -x^2+2*x*y  -x^2+x*y+y*x-y^2