anchor.diff:        true -> independent;
         false -> IrreversibleClock
       end,
  -  BaseNewClockMap = clock_map_store(state, StateClock, ClockMap),
  -  NewClockMap = clock_map_store(Actor, HappenedBeforeClock, BaseNewClockMap),
  +  BaseNewClockMap = map_store(state, StateClock, ClockMap),
  +  NewClockMap = map_store(Actor, HappenedBeforeClock, BaseNewClockMap),
     %% The HB clock should also be added to anything else stemming
     %% from the step (spawns, sends and deliveries)
     FinalClockMap =
  
positive.code:           #receive_event{receive_info = RI} -> RI;
            _ -> {system, fun(_) -> true end}
          end,
        Fold = fun(ID,Dict) -> dict:store(ID, ReceiveInfo, Dict) end,
        lists:foldl(Fold, ReceiveInfoDict, IDs)
    end.
  
  patch_message_delivery({message_delivered, MessageEvent}, ReceiveInfoDict) ->
    #message_event{message = #message{id = Id}} = MessageEvent,
    ReceiveInfo =
      case dict:find(Id, ReceiveInfoDict) of
        {ok, RI} -> RI;
        error -> not_received
      end,
  
negative.code: empty_map() ->
    dict:new().
  
  map_store(K, V, Map) ->
    dict:store(K, V, Map).
  
  map_find(K, Map) ->
    dict:find(K, Map).
  
  is_empty_map(Map) ->
    dict:size(Map) =:= 0.
  
  lookup_clock(P, ClockMap) ->
    case dict:find(P, ClockMap) of
  