anchor.diff:  		       (matrix-set *matrix* x y nil))
   		   (if (= count 3)
   		       (matrix-set *matrix* x y t)
  -		     'left-empty))))
  +		     'left-empty))
  +		 (draw-cell x y (matrix-get *matrix* x y))))
   	   *cells-count*))
   
   (defun game-count-alive (x1 y1)
  
positive.code:      ()
       (update-old-matrix)
       (game-step)
       (draw-matrix)
       (sdl:update-display)))))
  
  (defun init-settings ()
  
negative.code: 
  ;;; Draw
  ;;; ====
  
  (defun draw-cell (x y alive-p)
    (sdl:draw-box (sdl:rectangle-from-midpoint-* (* *cell-size* x)
  