anchor.diff:                CreationTimeStamp = Core.getTimeStamp ()
                 Xtension = Xtension.makeSafe ()
                 Dispatcher = dispatcher
  +              Depth = 0.0f
  +              Visible = true
  +              Persistent = true
                 ScriptOpt = None
                 Script = [||]
                 ScriptFrame = Scripting.DeclarationFrame HashIdentity.Structural
  
positive.code:               OnUnregister = Scripting.Unit
                OnUpdate = Scripting.Unit
                OnPostUpdate = Scripting.Unit
                OnSignal = Scripting.Unit
                TransitionState = IdlingState
                TransitionTicks = 0L // TODO: roll this field into Incoming/OutgoingState values
                Incoming = Transition.make Incoming
                Outgoing = Transition.make Outgoing
                Persistent = true }
  
          /// Try to get an xtension property and its type information.
          static member tryGetProperty propertyName screenState =
  
negative.code:           OnUnregister : Scripting.Expr
            OnUpdate : Scripting.Expr
            OnPostUpdate : Scripting.Expr
            OnSignal : Scripting.Expr }
            
          /// Make a screen state value.
          static member make nameOpt (dispatcher : ScreenDispatcher) =
  