Singular

D.15.6.3 multdivisor

Usage:

multdivisor(n ,A); A*n; n = integer, A = divisor.

Assume:

n is an integer and A is a divisor on X.

Return:

a divisor on X

Theory:

The procedure will compute the n-th power 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));
A;
divisor D = multdivisor(4,A);
D;
A*4;