FUNCTION: Perm2RRep - calculate the matrix representing a permutation in the regular representation

CALLING SEQUENCE:

Perm2RRep(perm)

SG[Perm2RRep](perm)

PARAMETERS:

perm = any list denoting a permutation

SYNOPSIS:

• The Perm2RRep function calculates the matrix representing perm in the regular representation. It amounts to consider perm as the linear operator acting on permutations by left multiplication.

• Whenever there is a conflict between the function name Perm2RRep and another name used in the same session, use the long form SG['Perm2RRep'].

EXAMPLES:

> with(SG):
> Perm2RRep([2,3,1]);
 
                             [ 0  0  0  0  1  0 ]
                             [                  ]
                             [ 0  0  0  0  0  1 ]
                             [                  ]
                             [ 0  1  0  0  0  0 ]
                             [                  ]
                             [ 1  0  0  0  0  0 ]
                             [                  ]
                             [ 0  0  0  1  0  0 ]
                             [                  ]
                             [ 0  0  1  0  0  0 ]
 
> RRep2Perm( Perm2RRep([2,3,1]) );
 
                                   [2, 3, 1]