i1 : R = ZZ/31[x, y, u, v] / ideal(x * y - u * v) o1 = R o1 : QuotientRing |
i2 : D1 = divisor({1, -2, 3, -4}, {ideal(x, u), ideal(x, v), ideal(y, u), ideal(y, v)}) o2 = 3*Div(y, u) + -4*Div(y, v) + 1*Div(x, u) + -2*Div(x, v) of R o2 : WDiv |
i3 : D2 = divisor({1, 39, 5, 27}, {ideal(x, v), ideal(y, v), ideal(x, u), ideal(x, u)}) o3 = 32*Div(x, u) + 39*Div(y, v) + 1*Div(x, v) of R o3 : WDiv |
i4 : isEffective( D1 ) o4 = false |
i5 : isEffective( D2 ) o5 = true |