faceFan -- computes the fan generated by the cones over the faces

i1 : P = hypercube 2

o1 = P

o1 : Polyhedron

i2 : F = faceFan P

o2 = F

o2 : Fan

i3 : raysF = rays F

o3 = | -1 1  -1 1 |
     | -1 -1 1  1 |

              2        4
o3 : Matrix ZZ  <--- ZZ

i4 : apply(maxCones F, mc -> raysF_mc)

o4 = {| -1 -1 |, | 1  1 |, | -1 1  |, | -1 1 |}
      | -1 1  |  | -1 1 |  | -1 -1 |  | 1  1 |

o4 : List