{
{   This routine  removes a permanent file root from the active set table.  If
{ there is no root stored no action is taken.  If there is a root stored it is
{ freed and the active set table entry is modified to reflect that there is no
{ longer a permanent file root stored for the set.
{
{       STP$PURGE_AST_PF_ROOT (AST_INDEX)
{
{ AST_INDEX: (input) This parameter specifies the index into  the  active  set
{       table for the set whose permanent file root is to be removed.
{
