up previous next
FrbAlexanderDual

Alexander Dual of monomial ideals

Syntax
FrbAlexanderDual(I: IDEAL): LIST
FrbAlexanderDual(I: IDEAL, T: RINGELEM): LIST

Description
Using the Frobby library linked with CoCoALib. Thanks to Bjarke Roune.

Example
/**/  use QQ[x,y,z];
/**/  I := ideal(x^2, x*y, y^2, z^2);
/**/  FrbAlexanderDual(I);
ideal(x^2*y*z, x*y^2*z)

/**/  FrbAlexanderDual(I, x^2*y^2*z^5);
ideal(x^2*y*z^4, x*y^2*z^4)

See Also