-- -*- M2-comint -*- hash: 7146482194105639427

i1 : R = QQ[x,y];

i2 : FA = EPY arrangement {x,y,x-y}

o2 = cokernel | -X_1 X_1+X_2+X_3 X_1     |
              | X_2  0           X_1+X_3 |

                                                2
o2 : QQ[X ..X ]-module, quotient of (QQ[X ..X ])
         1   3                           1   3

i3 : betti res FA

            0 1 2
o3 = total: 2 3 1
         0: 2 3 1

o3 : BettiTally

i4 : A = arrangement "prism"

o4 = {x , x , x , x , x  + x  + x , x  + x  + x }
       1   2   3   4   1    2    4   1    3    4

o4 : Hyperplane Arrangement 

i5 : reduceHilbert hilbertSeries orlikSolomon A

                 2      3     4
     1 + 6T + 15T  + 17T  + 7T
o5 = --------------------------
                  1

o5 : Expression of class Divide

i6 : betti res EPY A

            0  1  2 3 4
o6 = total: 7 17 15 6 1
         0: 7 17 15 6 1

o6 : BettiTally

i7 : 
