GAP Manual: 21.5. PermGroupOps.NrMovedPoints

PermGroupOps.NrMovedPoints( G )

PermGroupOps.NrMovedPoints returns the number of moved points of the permutation group G, i.e., points which are moved by at least one element of G (also see PermGroupOps.MovedPoints).

    gap> s4 := Group( (1,3,5,7), (1,3) );;
    gap> PermGroupOps.NrMovedPoints( s4 );
    4
    gap> PermGroupOps.NrMovedPoints( Group( () ) );
    0