A Weil divisor is
ℚ-Cartier if some positive integer multiple is Cartier.
On a simplicial toric variety, every torus-invariant Weil divisor is
ℚ-Cartier.
W = weightedProjectiveSpace {2,5,7}; |
isSimplicial W |
isCartier W_0 |
isQQCartier W_0 |
isCartier (35*W_0) |
In general, the
ℚ-Cartier divisors form a proper subgroup of the Weil divisors.
X = normalToricVariety(id_(ZZ^3) | -id_(ZZ^3)); |
isCartier X_0 |
isQQCartier X_0 |
K = toricDivisor X |
isCartier K |