anchor.diff:              let model = property.Get world
               this.View (model, layer, world)
   
  -        abstract member Binding : 'model * Layer * World -> Binding<'message, 'command, Layer, World> list
  +        abstract member Bindings : 'model * Layer * World -> Binding<'message, 'command, Layer, World> list
           abstract member Message : 'message * 'model * Layer * World -> 'model * 'command list
           abstract member Command : 'command * 'model * Layer * World -> World
           abstract member View : 'model * Layer * World -> World
  
positive.code:             let model = property.Get world
              this.View (model, entity, world)
  
          abstract member Binding : 'model * Entity * World -> Binding<'message, 'command, Entity, World> list
          abstract member Message : 'message * 'model * Entity * World -> 'model * 'command list
          abstract member Command : 'command * 'model * Entity * World -> World
          abstract member View : 'model * Entity * World -> World
  
negative.code:             let model = property.Get world
              this.View (model, screen, world)
  
          abstract member Bindings : 'model * Screen * World -> Binding<'message, 'command, Screen, World> list
          abstract member Message : 'message * 'model * Screen * World -> 'model * 'command list
          abstract member Command : 'command * 'model * Screen * World -> World
          abstract member View : 'model * Screen * World -> World
  