anchor.diff:                      true -> replay_trace(MightNeedReplayState);
                       false -> MightNeedReplayState
                   end,
  -	    Instruction = dict:fetch(SelectedLid, TraceTop#trace_state.nexts),
  +            Instruction = dict:fetch(SelectedLid, TraceTop#trace_state.nexts),
               NewDone = ordsets:add_element(SelectedLid, Done),
               NewTraceTop = TraceTop#trace_state{done = NewDone},
               NewState = State#dpor_state{trace = [NewTraceTop|RestTrace]},
  -	    {ok, Instruction, NewState}
  +            {ok, Instruction, NewState}
       end.
   
   replay_trace(#dpor_state{proc_before = ProcBefore,
  
positive.code:     ?f_debug("------------\nExplore ~p\n------------\n",
               [TraceTop#trace_state.i + 1]),
      case ordsets:subtract(Backtrack, Done) of
  	[] ->
              ?f_debug("Backtrack set explored\n",[]),
              none;
          [SelectedLid|_RestLids] ->
  
negative.code:             end
      end.
  
  -spec lid_from_pid(pid()) -> concuerror_lid:lid() | 'not_found'.
  
  lid_from_pid(Pid) ->
  