anchor.diff:              this.View.Bounds.Height - 50.0f,
               100.0f,
               44.0f)
  -        b.TouchUpInside.Add (fun x -> sv.Step())
  +        b.TouchUpInside.Add (fun x -> this.MySnakeView.Step())
           this.View.AddSubview(b)
   
           let lft = new UISwipeGestureRecognizer(Action<_> this.HandleSwipe)
  
positive.code:         | Left -> (x - 1, y)
          | Right -> (x + 1, y)
  
  
  [<Register("smallViewController")>]
  type smallViewController() = 
      inherit UIViewController()
  
      // Release any cached data, images, etc that aren't in use.
      override this.DidReceiveMemoryWarning() = 
  
negative.code: 
  
      member this.HandleSwipe(gr : UISwipeGestureRecognizer) =
          this.MySnakeView.MoveTowards <| 
          match gr.Direction with
          | UISwipeGestureRecognizerDirection.Up -> Up
          | UISwipeGestureRecognizerDirection.Left -> Left
          | UISwipeGestureRecognizerDirection.Right -> Right
          | UISwipeGestureRecognizerDirection.Down -> Down
          | _ -> Up
  
      // Return true for supported orientations
      override this.ShouldAutorotateToInterfaceOrientation(orientation) = 
  