anchor.diff:  (defmethod update-board ((this board-widget))
     (loop for row from 0 to 3 do
       (loop for col from 0 to 3 do
  -      (#_setText (index (board-labels this) row col) (write-to-string (index (board this) row col))))))
  +      (format t "TODO~%"))))
  +          ;      (#_setText (index (board-labels this) row col) (write-to-string (index (board this) row col))))))
   
   ; these methods each move the board in a specific direction
   ; they return whether or not they made any change at all
  
positive.code: (defun index (l row col)
    (nth col (nth row l)))
  
  ; make a board-widget class that derives from QWidget
  (defclass board-widget ()
    ((board :accessor board)
  
negative.code: ; make a new window
  (defun main ()
    (with-main-window (window (make-instance 'board-widget))
      (#_setStyleSheet window "background-color: #C2B39A;")
      (#_setFixedSize window 450 450)))
  
  ; call the main function
  (setf *random-state* (make-random-state t))
  