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
|