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D.5.4.11 makeFormalDivisor

Procedure from library divisors.lib (see divisors_lib).

Usage:
makeFormalDivisor(L); L = list.

Assume:
L is a list of tuples of an integer and a divisor.

Return:
a formal divisor on X

Theory:
Represents an integer formal sum of divisors.

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));
makeFormalDivisor(list(list(-5,A),list(2,B)));
==> -5*( (z,x) - (1) )
==> +2*( (y,x) - (1) )
==>