anchor.diff:  open System.Windows
   open FSharp.Qualia
   open System.Collections.ObjectModel
  +open System.Windows.Controls
   
   (**
   Collections
  
positive.code: 
  type Events = Add
  
  type ItemModel() =
      member val Text = ReactiveProperty("")
  
  type ItemView(elt, m) =
      inherit View<Events, FrameworkElement, ItemModel>(elt, m)
       override x.EventStreams = []
       override x.SetBindings m = ()
  type ListModel() =
      member val Items = new ObservableCollection<ItemModel>()
      
  type ListView(elt, m) =
      inherit View<Events, Window, ListModel>(elt, m)
      override x.EventStreams = []
      override x.SetBindings m = ()
  type ListController() =
  
negative.code:             function
              | Add -> Sync (fun m -> ())
  
  let w = new ListViewWindow()
  let app = if Application.Current = null then Application() else Application.Current
  let lm = ListModel()
  let v = ListView(w,lm)
  let c = ListController()
  let loop = EventLoop(v, c)
  loop.Start()
  