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D.15.6.16 degreeFormalDivisor

Procedure from library divisors.lib (see divisors_lib).

Usage:
degreeFormalDivisor(A); A = formaldivisor.

Assume:
A is a formaldivisor on X.

Return:
The degree of A.

Theory:
We compute degrees of the summands and return the weighted sum.

Example:
 
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));
formaldivisor fE= makeFormalDivisor(list(list(-5,A),list(2,B)));
degreeFormalDivisor(fE);