postulationNumber -- computes the largest degree at which the hilbert function of the graded module M is not equal to the hilbertPolynomial

Synopsis

• Usage:

  v = postulationNumber(M)

• Inputs:
  • M, a module, graded module
• Outputs:
  • v, an integer, largest degree at which the hilbert function of the graded module M is not equal to the hilbertPolynomial

Description

i1 : V = {{0,0},{1,0},{1,1},{0,1}};

i2 : F = {{0,1,2},{0,2,3}};

i3 : E = {{0,1},{0,2},{0,3},{1,2},{2,3}};

i4 : M = splineModule(V,F,E,2)

o4 = image | 1 t_0^3-3t_0^2t_1+3t_0t_1^2-t_1^3 |
           | 1 0                               |

                                                 2
o4 : QQ[t ..t ]-module, submodule of (QQ[t ..t ])
         0   2                            0   2

i5 : postulationNumber(M)

o5 = 0