anchor.diff:          model.OnPropertyChanged <@ model.Path @> displayPath
           model.OnPropertyChanged <@ model.PathFormat @> displayPath
   
  +        // display item in buffer
           window.BufferLabel.Content <- ""
           model.OnPropertyChanged <@ model.ItemBuffer @> (fun buffer ->
               let text = MainView.BufferStatus buffer
               window.BufferLabel.Content <- text
               window.BufferLabel.Visibility <- if text = "" then Visibility.Hidden else Visibility.Visible)
   
  +        // update command text selection
           model.OnPropertyChanged <@ model.CommandTextSelection @> (fun (start, len) ->
               window.CommandBox.Select(start, len))
   
  -        // bind to the command input mode to update the UI
  +        // update UI for the command input mode
           model.OnPropertyChanged <@ model.CommandInputMode @> (fun mode ->
               this.CommandInputModeChanged mode model.SelectedNode
               if mode.IsNone then model.CommandTextSelection <- (999, 0))
   
  -        // update controls to display status
  +        // update UI for status
           this.UpdateStatus model.Status
           model.OnPropertyChanged <@ model.Status @> this.UpdateStatus
   
  -        // bind tab to switching focus
  -        window.PathBox.PreviewKeyDown.Add (onKey Key.Tab window.NodeGrid.Focus)
  -        window.NodeGrid.PreviewKeyDown.Add (onKey Key.Tab (fun () ->
  +        // bind Tab key to switch focus
  +        window.PathBox.PreviewKeyDown.Add <| onKey Key.Tab window.NodeGrid.Focus
  +        window.NodeGrid.PreviewKeyDown.Add <| onKey Key.Tab (fun () ->
               window.PathBox.SelectAll()
  -            window.PathBox.Focus()))
  +            window.PathBox.Focus())
   
           // on selection change, keep selected node in view, make sure node list is focused
           window.NodeGrid.SelectionChanged.Add (fun _ ->
  
positive.code:                 window.CommandBox.Text <- model.CommandText |> BindingOptions.UpdateSourceOnChange
              @>
  
          let displayPath x =
              window.PathBox.Text <- model.PathFormatted
              window.Title <-
                  model.Path.Name
  
negative.code:         keyEvent |> Observable.choose (fun evt ->
              if evt.Key = key then
                  evt.Handled <- true
                  Some <| resultFunc()
              else
                  None)
  
  