anchor.diff:  	      (@ slider value) pos
   	      (@ (by-selector "#book-history-text") value) pos)
   	(hide! (by-selector ".book-title input"))
  -	(mirror! 
  -	 (by-selector ".book-title textarea")
  -	 :extra-keys
  -	 (create "Ctrl-]"     (lambda (mirror) 
  -				(let ((next (by-selector ".cells .cell")))
  -				  (when next
  -				    (hide-title-input)
  -				    (scroll-to-elem next)
  -				    (show-editor (elem->cell-id next)))))
  -		 "Ctrl-Enter" (lambda (mirror) (console.log "TODO - calling `/repackage-notebook`"))))
  -	(hide! (by-selector ".book-title .CodeMirror"))
  +	(setup-package-mirror!)
   	(set-page-hash (create :book id))))
   
       (defun notebook! (raw)
  
positive.code: 	    (when (relevant-event? res)
  	      (dom-replace (by-selector ".book-title") (notebook-title-template new-name))
  	      (set-notebook-name *notebook* new-name)
  	      (hide-title-input))
  	    (chain (by-selector (+ "#book-list option[value='" id "']")) (remove))
  	    (dom-append (by-selector "#book-list")
  
negative.code:       (let ((new-content (chain document (create-element "span")))
  	    (parent (@ elem parent-node)))
  	(setf (@ new-content inner-h-t-m-l) markup)
  	(loop for child in (@ new-content child-nodes)
  	   do (chain parent (insert-before new-content elem)))
  	(chain elem (remove))))
  
  