anchor.diff:  	     (setf corners (corners mirror))
   	     ;; Projection
   	     ((@ scene remove) projection)
  -	     (setf projection (projection mirror))
  +	     (setf projection (projection corners))
   	     ((@ scene add) projection)
   	     ;; Update absorbed arrow
   	     ((@ absorb-arrow set-length) (* 10 (/ absorbed 100)))))
  
positive.code: 	       (setf (@ ($ "#distance") 0 inner-h-t-m-l) ((@ ((@ *math floor10) pos -3) to-string)))
  	       (let* ((minutes (floor (/ elapsed 60)))
  		      (seconds (floor (- elapsed (* minutes 60)))))
  		 (setf (@ ($ "#elapsed") 0 inner-h-t-m-l) (+ ((@ minutes to-string)) (if (> seconds 9) ":" ":0") ((@ seconds to-fixed))))))
  	     ;; Move absorbed arrow
  	     ((@ absorb-arrow position copy) (@ sail position))
  	     ;; Update projection
  	     ((@ scene remove) projection)
  	     (setf projection (projection mirror))
  	     ((@ scene add) projection)
  	     ;;(funcall update-tilt)
  	     )
  	   animate
  	   (lambda ()
  	     (request-animation-frame animate)
  
negative.code: 	(setf
  	 mirror (mirror)
  	 corners (corners mirror)
  	 projection (projection corners)
  	 incident (incident)
  	 absorb-arrow (new (3fn *arrow-helper incident origin 10 0xffff00))
  	 visibility
  