anchor.diff:                 R1 ++ R2}
             end;
           error ->
  -          throw({error, erlang:error(io_lib:format("Unknown record #~w{}\n",
  -                                                   [Name]))})
  +          throw({error, io_lib:format("Unknown record #~w{}\n", [Name])})
         end;
       false -> {t_any(), []}
     end.
  
positive.code:       end;
      {opaque, {Module, Type, ArgNames}} when length(Args) =:= length(ArgNames) ->
        {Rep, Rret} =
          case unfold({opaque, Name}, TypeNames) of
            true ->
              List = lists:zipwith(
                       fun(ArgName, ArgType) ->
  
negative.code:     [] -> inf_tuple_sets(Left1, Left2, Acc, Mode);
      NewTuples -> inf_tuple_sets(Left1, Left2, [{Arity, NewTuples}|Acc], Mode)
    end;
  inf_tuple_sets([{Arity1, _}|Ts1] = L1, [{Arity2, _}|Ts2] = L2, Acc, Mode) ->
    if Arity1 < Arity2 -> inf_tuple_sets(Ts1, L2, Acc, Mode);
       Arity1 > Arity2 -> inf_tuple_sets(L1, Ts2, Acc, Mode)
    end;
  inf_tuple_sets([], _, Acc, _Mode) -> lists:reverse(Acc);
  inf_tuple_sets(_, [], Acc, _Mode) -> lists:reverse(Acc).
  