anchor.diff:  %% functions.
   driver(#info{active = Active, blocked = Blocked, error = Error,
                reason = Reason, state = State} = Info, ReplayState) ->
  -    %% Assertion violation check.
       case Error of
   	assert -> {error, assert, Reason, State};
           exception -> {error, exception, Reason, State};
  
positive.code:     Parent ! {interleave_result, {Result, Time}}.
  
  %% Main loop for producing process interleavings.
  interleave_loop(Target, RunCnt, Tickets, Det) ->
      %% Lookup state to replay.
      case state:load() of
  
negative.code:     ?RP_SCHED ! #sched{msg = spawn, pid = self(), misc = Pid},
      rep_yield(),
      Pid.
  
  %% Wait until the scheduler prompts to continue.
  -spec wait() -> 'true'.
  
  wait() ->
      receive
  	#sched{msg = continue} -> true
      end.
  