GAP Manual: 27.29. SortParallel

SortParallel( list1, list2 )
SortParallel( list1, list2, func )

SortParallel sorts the list list1 in increasing order just as Sort (see Sort) does. In parallel it applies the same exchanges that are necessary to sort list1 to the list list2, which must of course have at least as many elements as list1 does.

    gap> list1 := [ 5, 4, 6, 1, 7, 5 ];;
    gap> list2 := [ 2, 3, 5, 7, 8, 9 ];;
    gap> SortParallel( list1, list2 );
    gap> list1;
    [ 1, 4, 5, 5, 6, 7 ]
    gap> list2;
    [ 7, 3, 2, 9, 5, 8 ]    # '[ 7, 3, 9, 2, 5, 8 ]' is also possible 

Sortex (see Sortex) sorts a list and returns the sorting permutation.