D.2.4.5 is_zero

Procedure from library poly.lib (see poly_lib).

Usage:

is_zero(M[,any]); M=poly/ideal/vector/module/matrix

Return:

integer, 1 if coker(M)=0 resp. 0 if coker(M)!=0, where M is considered as matrix.
If a second argument is given, return a list:
L[1] = 1 if coker(M)=0 resp. 0 if coker(M)!=0
L[2] = dim(M)

Example:

LIB "poly.lib";
ring r;
module m = [x],[y],[1,z];
is_zero(m,1);
→ [1]:
→    0
→ [2]:
→    2
qring q = std(ideal(x2+y3+z2));
ideal j = x2+y3+z2-37;
is_zero(j);
→ 1