anchor.diff:  
   /// Descends into Skel and updates dirty nodes.
   let update parent skel =
  +    // Gets the position of sk relative to a DOM node
       let rec posOf sk =
           match sk with
           | S0 -> AtEnd
  
positive.code:     let attrs = Attrs.Concat [Attrs.Create "type" "button"; Attrs.Create "value" caption]
      element el attrs Empty
  
  let ForEach input render =
      let mRender = memo render
      input
      |> R.View.Map (List.map mRender >> Concat)
      |> EmbedView
  
  let RenderCollection<'T> (coll : ReactiveCollection<'T>) (render : ReactiveCollection<'T> -> 'T -> Tree) =
      // Trigger rendering function on each item in the collection
      ViewCollection coll
      |> R.View.Map (fun map ->
          Map.fold (fun s _ v -> (render coll v) :: s) [] map
  
negative.code: 
  /// Embedding dynamic nodes.
  let EmbedView v =
      // Create initial variable skeleton information
      let sk =
          {
              BeforeSkel = S0
  