# trim(BasicDivisor) -- trims the ideals displayed to the user and removes primes with coefficient zero

## Description

This function returns a divisor where all entries with coefficient zero are removed and where the ideals displayed to the user are trimmed.

 i1 : R = QQ[x,y,z]/ideal(x*y-z^2); i2 : D = divisor({1,0,-2}, {ideal(x, z), ideal(x-z,y-z), ideal(y+z, z)}); o2 : WeilDivisor on R i3 : cleanSupport(D) o3 = -2*Div(y+z, z) + Div(x, z) o3 : WeilDivisor on R i4 : trim(D) o4 = -2*Div(z, y) + Div(z, x) o4 : WeilDivisor on R i5 : D == trim(D) o5 = true