anchor.diff:  
   type Easing = Func<float, float, float, float, float>
   
  +// For performance, we use delegates instead of curried F# functions
   type Behavior = Func<ESprite, float, Promise<bool>>
   
   and ESprite(t:Texture, id: string, behaviors: Behavior list) =
  
positive.code:             
      // Create our sprites
      let sprites =
          [0 .. 100]
          |> List.map (string >> createSprite texture renderer.width renderer.height)
  
      // Add sprites to stage and make some funny homing missiles
      sprites
  
negative.code:         _behaviors <- _behaviors @ notCompletedBehaviors
      }
  
      // System.IDisposable is the usual interface for disposable objects
      // in C#/F#. It lets you use language constructs like `use`. 
      interface IDisposable with
          member self.Dispose() =
              if not _disposed then
  