anchor.diff:  	      (chain (notebook-facts *notebook*) (unshift (list id 'cell nil)))
   	      (dom-append (by-selector ".cells")
   			  (cell-template cell))
  -	      (mirror! cell)
  +	      (setup-cell-mirror! cell)
   	      (scroll-to-elem (by-cell-id id))
   	      (show-editor id))))
   	'change-cell-type
  
positive.code: 	  (cell-code-template cell)))
      
      (defun show-title-input () 
        (let ((input (by-selector ".book-title input"))))
        (show! input)
        (chain input (focus))
        (chain input (select))
        (hide! (by-selector ".book-title h1")))
  
      (defun hide-title-input () 
        (hide! (by-selector ".book-title input"))
        (show! (by-selector ".book-title h1")))
      
      (defun notebook-title-template (name)
        (who-ps-html
         (:div :class "book-title"
  	     (:input :class "text" :onchange "renameBook(this.value)" :value name)
  	     (:h1 :onclick "showTitleInput()" name))))
  
      (defun notebook-template (notebook)
  
negative.code:     
      (defun dom-replace-cell (cell)
        (dom-replace (by-cell-id (@ cell id)) (cell-template cell))
        (setup-cell-mirror! cell))
  
      ;; CodeMirror and utilities
      (defun register-helpers (type object)
  