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OldPolyhedra :: hirzebruch

hirzebruch -- computes the fan of the r-th Hirzebruch surface

Synopsis

Description

The r-th Hirzebruch surface is the Fan in QQ^2 generated by the cones <e_1,e_2>, <e_1,-e_2>, <-e_1+r*e_2,-e_2> and <-e_1+r*e_2,e_2>.

i1 : F = hirzebruch 3

o1 = {ambient dimension => 2         }
      number of generating cones => 4
      number of rays => 4
      top dimension of the cones => 2

o1 : Fan
i2 : apply(maxCones F,rays)

o2 = {| 0 -1 |, | 1 0 |, | 1 0  |, | 0  -1 |}
      | 1 3  |  | 0 1 |  | 0 -1 |  | -1 3  |

o2 : List

Ways to use hirzebruch :

For the programmer

The object hirzebruch is a method function.