anchor.diff:              subscriptionId
   
       member this.Subscribe<'d, 'w when 'w :> Freezable> eventName callback =
  -        this.SubscribePlus<'d> Gen.id eventName (fun evt system ecs world -> callback evt system ecs; world) |> ignore
  +        this.SubscribePlus<'d> Gen.id eventName (fun evt system ecs worldOpt -> callback evt system ecs; worldOpt) |> ignore
   
       member this.Unsubscribe eventName subscriptionId =
           match systemSubscriptions.TryGetValue eventName with
  
positive.code:     do this.RegisterSystemGeneralized globalSystem
  
      member private this.BoxCallback<'a> (callback : SystemCallback<'a, 'w>) =
          let boxableCallback = fun (evt : SystemEvent<obj, 'w>) world ->
              let evt =
                  { SystemEventData = evt.SystemEventData :?> 'a
                    SystemPublisher = evt.SystemPublisher }
              callback evt world
          boxableCallback :> obj
  
      member private this.Correlations 
  
negative.code:     new (buffered, ecs) = SystemCorrelated (typeof<'c>.Name, buffered, ecs)
  
      member this.Components with get () = components
      member this.WithComponentsBuffered (fn : 'c ArrayRef -> 'w option -> 'w option) worldOpt = lock componentsBuffered (fun () -> fn componentsBuffered worldOpt)
  
      member this.GetJunction<'c> () = junctions |> Array.find SystemCorrelated<'c, 'w>.isJunction<'c> :?> 'c ArrayRef
      member this.WithJunctionBuffered<'c> fn (worldOpt : 'w option) = let junction = this.GetJunction<'c> () in  lock junction (fun () -> fn junction worldOpt)
  
      member private this.Compact ecs =
  
  