anchor.diff:                           supervisor:child_spec())
                  -> supervisor:startchild_ret().
   start_sup_as_child(Prefix, AtSup, SupAsChild) ->
  -    progress(Prefix ++ "supervisor ~.0p ~.0p~n",
  +    progress(Prefix ++ "supervisor ~.0p ~.0p",
                [element(1, SupAsChild), element(2, SupAsChild)]),
       Module = element(1, element(2, SupAsChild)),
       Args = element(3, element(2, SupAsChild)),
  
positive.code:             Res = supervisor:start_child(SupRef, Child),
              _ = case Res of
                  {ok, undefined} ->
                      progress("not started~n");
                  {ok, Pid} -> progress("~p.~n", [Pid]);
                  {ok, Pid, GroupInfo} ->
                          progress("~.0p ~.0p.", [Pid, GroupInfo]);
                  Error ->
                      progress("~nFailed to start ~p reason ~p~n", [Child, Error]),
                      progress("Supervisor ~p has childs: ~p~n",
                                [SupRef, sup_which_children(SupRef)]),
                      Error
              end,
  
negative.code:             SupRef = element(2, X),
              case SupSpec of
                  unknown_supspec ->
                      progress(PipePrefix ++ "started childs at ~.0p:~n",
                               [SupRef]),
                      show_started_childs(PipePrefix ++ ["+-"], SupRef),
                      Res;
                  _ ->
                      progress(PipePrefix
                               ++ "~.0p ~.0p", [SupSpec, SupRef]),
                      Childs = trycall(PipePrefix, Module, childs, Args, []),
                      ChildsRes = add_childs(PipePrefix ++ ["+-"], SupRef, Childs),
                      if is_tuple(ChildsRes) andalso element(1, ChildsRes) =:= ok ->
                             Res; %% return pid of supervisor as it may be linked to externally;
                         true ->
                             io:format("Startup raised ~.0p.~n", [ChildsRes]),
                             SupName = element(1, SupAsChild),
                             sup_terminate_childs(SupRef),
                             _ = supervisor:terminate_child(AtSup, SupName),
  