-- -*- M2-comint -*- hash: 8310115974601651486

i1 : A = arrangement "MacLane";

i2 : poincare A

                 2      3
o2 = 1 + 8T + 20T  + 13T

o2 : ZZ[T]

i3 : characteristicPolynomial matroid A

      3     2
o3 = x  - 8x  + 20x - 13

o3 : ZZ[x]

i4 : factor poincare typeA 3

o4 = (1 + T)(1 + 2T)(1 + 3T)

o4 : Expression of class Product

i5 : A = arrangement "Hessian";

i6 : factor poincare A

o6 = (1 + T)(1 + 4T)(1 + 7T)

o6 : Expression of class Product

i7 : prune image der A

        ZZ          3
o7 = (-----[x ..x ])
      31627  1   3

       ZZ
o7 : -----[x ..x ]-module, free, degrees {1, 4, 7}
     31627  1   3

i8 : 
