allNefContractions -- produces all contractions corresponding to each face in the nef cone

• Usage:

  nefRayContractions X

• Inputs:
  • X, a normal toric variety,
• Outputs:
  • a list, of ToricMaps obtained by contracting a face of the nef cone

i1 : X = hirzebruchSurface 1;

i2 : L = allNefContractions X

o2 = {| 1 0 |, | 1 0 |, | 1 0 |}
               | 0 1 |  | 0 1 |

o2 : List

i3 : assert(all(L, phi -> isWellDefined phi))