anchor.diff:              this.View (Actualize, model, screen, world)
   
           abstract member Binding : 'model * Screen * World -> Binding<'message, 'effect, Screen, World> list
  -        abstract member Message : 'message * 'model * Screen * World -> 'model * (World -> World)
  +        abstract member Message : 'message * 'model * Screen * World -> 'model * 'effect option
           abstract member Effect : 'effect * 'model * Screen * World -> World
           abstract member View : Phase * 'model * Screen * World -> World
   
  
positive.code:             this.View (Actualize, model, layer, world)
  
          abstract member Binding : 'model * Layer * World -> Binding<'message, 'effect, Layer, World> list
          abstract member Message : 'message * 'model * Layer * World -> 'model * (World -> World)
          abstract member Effect : 'effect * 'model * Layer * World -> World
          abstract member View : Phase * 'model * Layer * World -> World
  
  
negative.code:             this.View (Actualize, model, entity, world)
  
          abstract member Binding : 'model * Entity * World -> Binding<'message, 'effect, Entity, World> list
          abstract member Message : 'message * 'model * Entity * World -> 'model * 'effect option
          abstract member Effect : 'effect * 'model * Entity * World -> World
          abstract member View : Phase * 'model * Entity * World -> World
  
  