anchor.diff:    if
       Tag1 < Tag2   -> decorate_tuples_in_sets(Tuples, L2, Opaques, [T1|Acc]);
       Tag1 > Tag2   -> decorate_tuples_in_sets(L1, Ts, Opaques, Acc);
  -    Tag1 =:= Tag2 ->
  +    Tag1 == Tag2 ->
         NewElements = list_decorate(Elements, Es, Opaques),
         NewAcc = [?tuple(NewElements, Arity, Tag1)|Acc],
         decorate_tuples_in_sets(Tuples, Ts, Opaques, NewAcc)
  
positive.code: t_sup(?tuple_set(_), ?tuple(?any, ?any, ?any) = T) -> T;
  t_sup(?tuple(Elements1, Arity, Tag1) = T1,
        ?tuple(Elements2, Arity, Tag2) = T2) ->
    if Tag1 =:= Tag2 -> t_tuple(t_sup_lists(Elements1, Elements2));
       Tag1 =:= ?any -> t_tuple(t_sup_lists(Elements1, Elements2));
       Tag2 =:= ?any -> t_tuple(t_sup_lists(Elements1, Elements2));
       Tag1 < Tag2 -> ?tuple_set([{Arity, [T1, T2]}]);
       Tag1 > Tag2 -> ?tuple_set([{Arity, [T2, T1]}])
    end;
  
negative.code:   if
      Tag1 < Tag2   -> sup_tuples_in_set(Left1, L2, [T1|Acc]);
      Tag1 > Tag2   -> sup_tuples_in_set(L1, Left2, [T2|Acc]);
      Tag1 == Tag2 ->
        NewElements = t_sup_lists(Elements1, Elements2),
        NewAcc = [?tuple(NewElements, Arity, Tag1)|Acc],
        sup_tuples_in_set(Left1, Left2, NewAcc)
    end;
  sup_tuples_in_set([], L2, Acc) -> lists:reverse(Acc, L2);
  sup_tuples_in_set(L1, [], Acc) -> lists:reverse(Acc, L1).
  