D.15.5.2 divisorplus

Usage:

divisorplus(A ,B); A + B; A = divisor, B = divisor.

Assume:

A and B are divisors on X.

Return:

a divisor on X

Theory:

The procedure will compute the product of the numerator and denominator ideals, respectively.

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));
A+B;