anchor.diff:  %% remains in the active set.
   handler(yield, Pid, #info{active = Active} = Info, _Opt) ->
       Lid = lid(Pid),
  -    debug("Process ~p yields.~n", [Lid]),
  +    ?debug("Process ~p yields.~n", [Lid]),
       NewActive = set_add(Active, Lid),
       Info#info{active = NewActive}.
   
  
positive.code: 	    Next = search(Info),
  	    %% Remove process Next from the `active` set and run it.
  	    NewActive = set_remove(Active, Next),
  	    debug("Running process ~p.~n", [Next]),
  	    run(Next),
  	    %% Create new state.
  	    NewState = state_get_next(State, Next),
  
negative.code: 	false ->
  	    %% Remove process Next from the `active` set and run it.
  	    NewActive = set_remove(Active, Next),
  	    ?debug("Running process ~p.~n", [Next]),
  	    run(Next),
  	    %% Create new state.
  	    NewState = state_get_next(State, Next),
  