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ArrPoincarePoly    --    Poincare polynomial of an arrangement of hyperplanes

Syntax

ArrPoincarePoly(A: LIST): RINGELEM

Description

This function returns the Poincare polynomial from the list A of hyperplanes in the arrangement in the variable t.

Example

/**/ use QQ[x,y]; /**/ A := [x, x-y, y]; /**/ ArrPoincarePoly(A); 2*t^2 +3*t +1

See Also

• PosetPoincarePoly
• ArrCharPoly