anchor.diff:        (let ((new-content (chain document (create-element "span")))
   	    (parent (@ elem parent-node)))
   	(setf (@ new-content inner-h-t-m-l) markup)
  -	(loop for elem in (@ new-content child-nodes)
  +	(loop for child in (@ new-content child-nodes)
   	   do (chain parent (insert-before new-content elem)))
   	(chain elem (remove))))
   
  
positive.code:     (defun notebook-cell (notebook id)
        (aref notebook :objects id))
      
      (defun surgical! (raw)
        (let* ((slider (by-selector "#book-history-slider"))		     
  	     (count (@ raw history-size))
  
negative.code: 	    (when (relevant-event? res)
  	      (dom-replace (by-selector ".book-title") (notebook-title-template new-name))
  	      (set-notebook-name *notebook* new-name)
  	      (setup-package-mirror!)
  	      (hide-title-input))
  	    (chain (by-selector (+ "#book-list option[value='" id "']")) (remove))
  	    (dom-append (by-selector "#book-list")
  