i1 : R = ZZ/7[x,y,z]/ideal(x^3+y^3+z^3) o1 = R o1 : QuotientRing
i2 : idealToDivisor( ideal(x) ) o2 = -1*Div(y+2*z, x) + -1*Div(y-3*z, x) + -1*Div(y+z, x) of R o2 : WDiv
i3 : idealToDivisor( ideal(x, y+z) ) o3 = -1*Div(y+z, x) of R o3 : WDiv