{
{   The purpose  of  this routine is to determine if a set is active.  This is
{ done by searching the active set table keyed by set name.   If  the  set  is
{ found  in the active set table, the index and a copy of the active set table
{ entry is returned.
{
{       STP$SEARCH_AST_BY_SET (SET_NAME_KEY, FOUND_AST_ENTRY, FOUND_AST_INDEX,
{         SET_KEY_FOUND)
{
{ SET_NAME_KEY: (input) This parameter specifies the name of the set to search
{       for.
{
{ FOUND_AST_ENTRY: (output)  If  set_key_found  =  TRUE  then  this  parameter
{       returns the active set table entry for the found set.
{
{ FOUND_AST_INDEX:  (output)  IF  set_key_found  =  TRUE  then  this parameter
{       returns the index into the active set table for that set.
{
{ SET_KEY_FOUND: (output) This parameter returns whether the set was found  to
{       be active, that is in the active set table.
{
