D.15.1.41 arrPoincare

Usage:

arrPoincare(A); arr A

Return:

[intvec] The Poincare polynomial as integer vector of the arrangement, which is equal to the second kind Poincare-Series of the Orlik-Solomon Algebra.

LIB "arr.lib";
ring R = 0,(x,y,z,u,v),dp;
arr A = arrBraid(5);
intvec v = arrPoincare(A);
(1+x)*(1+2x)*(1+3x)*(1+4x);
==> 24x4+50x3+35x2+10x+1
v;
==> 1,10,35,50,24