anchor.diff:    {MessageOrAfter, ReceiveInfo} =
       has_matching_or_after(PatternFun, Timeout, Location, Info, blocking),
     #concuerror_info{
  -     next_event = NextEvent,
  +     event = NextEvent,
        flags = #process_flags{trap_exit = Trapping}
       } = UpdatedInfo =
       add_location_info(Location, ReceiveInfo),
  
positive.code:   #concuerror_info{
       flags = #process_flags{trap_exit = TrapExit},
       links = Links,
       next_event = #event{event_info = EventInfo} = Event} = Info,
    case run_built_in(erlang, is_process_alive, 1, [Pid], Info) of
      {true, Info}->
        Self = self(),
  
negative.code:   run_built_in(erlang, spawn_opt, 1, [{M, F, Args, [link]}], Info);
  run_built_in(erlang, spawn_opt, 1, [{Module, Name, Args, SpawnOpts}], Info) ->
    #concuerror_info{
       event = Event,
       processes = Processes,
       timeout = Timeout} = Info,
    #event{event_info = EventInfo} = Event,
  