ListPerm( perm )
ListPerm returns a list list that contains the images of the positive
integers under the permutation perm. That means that list[i] =
i^perm, where i lies between 1 and the largest point moved by
perm (see LargestMovedPointPerm).
gap> ListPerm( (1,2,3,4) );
[ 2, 3, 4, 1 ]
gap> ListPerm( () );
[ ]
PermList (see PermList) performs the inverse operation.
GAP 3.4.4