anchor.diff:      NewNexts = dict:store(Lid, Next, Nexts),
       {NewEnabled, NewBlocked} =
           update_lid_enabled(Lid, Next, Enabled, Blocked),
  -    WakedSleepSet = remove_awaked(SleepSet, Nexts, Selected),
  -    NewSleepSet =
  -        case dict:find(Lid, SleepMap) of
  -            error -> WakedSleepSet;
  -            {ok, NewSleeping} ->
  -                ?f_debug("Sleeping: ~w\n",[NewSleeping]),
  -                ordsets:union(NewSleeping, WakedSleepSet)
  -        end,        
  +    NewSleepSet = remove_awaked(SleepSet, Nexts, Selected),
       CommonNewTraceTop =
           #trace_state{i = NewN, last = Selected, nexts = NewNexts,
                        enabled = NewEnabled, blocked = NewBlocked,
  
positive.code:                 end
          end,
      {ok, Pick, _Clock} = lists:foldl(Fold, none, Candidates),
      {one, Pick}.
  
  update_sleep_map(Procs, SleepThis, SleepMap) ->
      Update =
          fun(OldSleeps) ->
              ordsets:add_element(SleepThis, OldSleeps)
          end,
      Init = ordsets:from_list([SleepThis]),
      Fold =
          fun(P, Dict) ->
              dict:update(P, Update, Init, Dict)
          end,
      lists:foldl(Fold, SleepMap, Procs).
  
  %% - add new entry with new entry
  %% - wait any possible additional messages
  
negative.code:                     link(Pid),
                      Pid ! ?VECTOR_MSG(Lid, VC),
                      receive
                          ?VECTOR_MSG(_PidsLid, ok) -> ok;
                          {'EXIT', Pid, _Reason} ->
                              %% Process may have been asked to exit.
                              ok                                                        
  