let pp_userdef_descr fmt d =
      begin
        if d.d_implicit <> [] then
          begin
            Format.fprintf fmt "Locations:" ;
            pp_closures fmt d.d_implicit d.d_closure ;
          end ;
        if d.d_implicit <> [] && d.d_formals <> [] then
          Format.pp_print_newline fmt () ;
        if d.d_formals <> [] then
          begin
            Format.fprintf fmt "Parameters:" ;
            pp_formals fmt d.d_formals
          end ;
      end