{
{This procedure is the inteface procedure to display all the variable
{names in a procedure, regardless of the language.  It was designed to be
{called by dup$display_variable, but could be called by any procedure that
{can generate the appropriate calling sequence.  This procedure calls
{subordinate procedures that are specific to each language to determine
{what variables qualify for $ALL for a particular language.  This procedure
{performs the central service of outputting display headers.
{
{Calling sequence:
{
{     home_spec: dut$home_specification (input) This procedure expects the
{        language field to be meaningful, as well as the procedure_entry field
{        Subordinate procedures may expect other fields to be valid
{
{     display_type: dut$display_type (input) This parameter specifies the
{        format in which the variables are to be displayed.
{
{     p_variant_selection: ^clt$data_value (input) This parameter specifies
{        a list of variant selections (possibly NIL) for use in fixing tagless
{        variant records.
{
{     display_control_pointer: ^clt$display_control (input,output) This
{       is a pointer to the display control block for the output file to
{       which the display is to be directed
{
{     status: ost$status (output) Status variable
{       due$all_not_implemented - Debug cannot support displaying all
{         variables in a procedure written in this language
{       due$internal_error - Covers unanticipated situations in the
{         code
{       Status variables set by subordinate procedures are not altered, but
{         are passed along
{

