LOCAL
    the_reverse : oriented_closed_shell;
  END_LOCAL;
   IF ('TOPOLOGY_SCHEMA.ORIENTED_CLOSED_SHELL' IN TYPEOF (a_shell) ) THEN
      the_reverse := dummy_tri ||
                    connected_face_set (
                       a_shell\connected_face_set.cfs_faces) ||
                    closed_shell () || oriented_closed_shell(
                     a_shell\oriented_closed_shell.closed_shell_element,
                       NOT(a_shell\oriented_closed_shell.orientation));
   ELSE
      the_reverse := dummy_tri ||
               connected_face_set (
                 a_shell\connected_face_set.cfs_faces) ||
               closed_shell () || oriented_closed_shell (a_shell, FALSE);
   END_IF;
   RETURN (the_reverse);