{
{   The purpose of this request is to return a list of all active sets.
{ The set manager defines an active set to be a set with at least one
{ volume active.
{
{       STP$GET_ACTIVE_SET_LIST (ACTIVE_SET_LIST, ACTUAL_NUMBER_OF_SETS,
{         STATUS)
{
{ ACTIVE_SET_LIST: (output) This parameter returns the list of active sets.
{           IF actual_number_of_sets = UPPERBOUND (active_set_list) THEN
{             All sets have been gotten.
{           IF actual_number_of_sets < UPPERBOUND (active_set_list) THEN
{             Only the actual number of sets are stored in the lower portion
{             of the array.  All other array entries (the upper portion) are
{             undefined.
{           IF actual_number_of_sets > UPPERBOUND (active_set_list) THEN
{             The active_set_list is filled with sets, but is not big enough
{             There are (actual_number_of_sets - UPPERBOUND(active_set_list))
{             additional sets in the set.
{           IF actual_number_of_sets = 0 THEN
{             There are no active sets.
{
{ ACTUAL_NUMBER_OF_SETS: (output) This returns the number of sets known
{         by the set manager.
{
