anchor.diff:  driver(Context, ReplayState) ->
       case state:is_empty(ReplayState) of
           true -> driver_normal(Context);
  -        false ->
  -            ?f_debug("Replay..."),
  -            driver_replay(Context, ReplayState)
  +        false -> driver_replay(Context, ReplayState)
       end.
   
   driver_replay(Context, ReplayState) ->
  
positive.code:     #context{blocked = NewBlocked} = NewContext,
      case state:is_empty(Rest) of
          true ->
              ?f_debug("done\n"),
              case ?SETS:is_element(Next, NewBlocked) of
                  %% If the last action of the replayed state prefix is a block,
                  %% we can safely abort.
                  true ->
                      ?f_debug("I am a hidden interleaving! :-P\n"),
                      abort;
                  %% Replay has finished; proceed in normal mode, after checking
                  %% for errors during the last replayed action.
                  false -> check_for_errors(NewContext)
  
negative.code:     Next =
          case ?SETS:is_element(LastLid, Active) of
              true ->
                  TmpActive = ?SETS:to_list(?SETS:del_element(LastLid, Active)),
                  {LastLid,TmpActive, next};
              false ->
                  [Head|TmpActive] = ?SETS:to_list(Active),
                  {Head, TmpActive, current}
          end,
      {NewContext, Insert} = run_no_block(Context, Next),
  