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D.15.13.2 divisorplus

Procedure from library divisors.lib (see divisors_lib).

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.

Example:
 
LIB "divisors.lib";
==> Welcome to polymake version
==> Copyright (c) 1997-2015
==> Ewgenij Gawrilow, Michael Joswig (TU Darmstadt)
==> http://www.polymake.org
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;
==> (x,yz) - (1)
==>