/* Check for back-level table                                     */
   "TBQUERY" @tn@ "NAMES(NAMELIST)"
   parse var namelist "(" namelist ")"
   if WordPos("CPMLIB",namelist) = 0 then do
      /* call TBCOPY to rebuild the back-level table                 */
      address TSO "TBCOPY" @tn@ "TYPE CP REPLACE FROM" isptlib
      call BA_PROLOG                   /* reopen table              -*/
      end                              /* back_level table           */