Singular

D.15.6.6 isEqualDivisor

Usage:

isEqualDivisor(A,B); A = divisor, B = divisor.

Assume:

A and B are divisors on X.

Return:

int 0 or 1, checks equality of A and B.

Theory:

The procedure will compute the normal forms of A and B and compare.

LIB "divisors.lib";
ring r=31991,(x,y,z),dp;
ideal I = y^2*z - x*(x-z)*(x+3*z);
qring Q = std(I);
divisor A = makeDivisor(ideal(x,z),ideal(1));
divisor B = makeDivisor(ideal(x,y),ideal(1));
divisor D = (A+B)+multdivisor(-1,B);
isEqualDivisor(A,D);