permute(List,DivisorClassRepresentativeM0nbar) -- compute the image of a divisor class representative under a permutation of the marked points

Synopsis

Function: permute
Usage:

permute(sigma,D)
Inputs:
- sigma, a list
- D, an instance of the type DivisorClassRepresentativeM0nbar
Outputs:
- D2, an instance of the type DivisorClassRepresentativeM0nbar

Description

The symmetric group $S_n$ acts on $\bar{M}_{0,n}$ by permuting the marked points.

This function computes the image of a divisor class representative $C$ under a permutation $\sigma$ of the marked points.

Enter $\sigma$ as a list $\{ \sigma(1),\sigma(2),\ldots,\sigma(n)\}$. Cycle class notation is not supported for this function.

i1 : L= { {{1,3},1}, {{1,4},-3}};

i2 : D=divisorClassRepresentativeM0nbar(5,L);

i3 : permute({5,2,1,3,4}, D)

o3 = DivisorClassRepresentativeM0nbar{DivisorExpression => HashTable{{1, 5} => 1 }}
                                                                     {3, 5} => -3
                                      NumberOfMarkedPoints => 5

o3 : DivisorClassRepresentativeM0nbar