anchor.diff:  (defun new-game ()
     (reset-x-o)
     (unmark-row)
  -  (h:hset *cells* :text ""))
  +  (h:hset *cells* :text "")
  +  (when (eql :computer *player-1*)
  +    (computer-move)))
   
   (defun move (web-element)
     (when (and (not (won))
  
positive.code:     (h:hset web-element :text (x-o))
      (check-win)
      (when (and (not (won))
                 *computer-player*
        (computer-move)))))
  
  (defun s (&rest numbers)
    "Sum of binary shifted numbers."
  
negative.code: (defvar *cells*    "[class='cells']")
  (defvar *new-game* "#new-game")
  
  (defvar *cell-count* 9)
  (defvar *player-1*   :human)
  (defvar *player-2*   :computer)
  
  (defun cell-id (index)
    (format nil "#c~D" (1+ index)))
  