anchor.diff:  
   %% -define(DEBUG, true).
   %% -define(STEPWISE, true).
  -%% -define(STATS, true).
  +-define(STATS, true).
  +-define(STACK, true).
   
   -ifdef(DEBUG).
  +-ifndef(STACK).
   -define(STACK, true).
  +-endif.
   -endif.
   
   %%------------------------------------------------------------------------------
  
positive.code: 
  max_dependent(_Cmd, [], _ClockMap, Acc) -> Acc;
  max_dependent(Cmd1, [#state{i = N, last = Cmd2}|Trace], ClockMap, Acc) ->
    case dependent(Cmd1, Cmd2) of
      true ->
        CI = lookup_clock(N, ClockMap),
        Merger = fun(_Key, V1, V2) -> max(V1, V2) end,
  
negative.code:     case pick_random_enabled(Trace) of
        none ->
          %% TODO: Report Check for deadlocks
          ?show_stack(Trace),
          ?stats_inc,
          UpdatedTrace;
        {ok, P} ->
  