anchor.diff:  	 corners (corners mirror)
   	 projection (projection corners)
   	 incident (incident)
  -	 absorb-arrow (new (3fn *arrow-helper incident origin 10 0xff0000))
  +	 absorb-arrow (new (3fn *arrow-helper (incident) ((@ (incident) multiply-scalar) -10) 10 0xffff00))
   	 visibility
   	 (let ((visibility-super ((@ app superior) "visibility")))
   	   (lambda (bool)
  
positive.code: 	     (setf projection (projection corners))
  	     ((@ scene add) projection)
  	     ;; Update absorbed arrow
  	     ((@ absorb-arrow set-length) (* 10 (/ absorbed 100)))))
  	 )
  	;; Add objects
  	((@ sail add) mirror)
  
negative.code: 	     (lambda ()
  	       (funcall init-super)
  	       ((@ sail-position add) force-arrow)
  	       ((@ sail-position add) absorb-force-arrow)
  	       ((@ sail-position add) reflect-arrow)))
  	   visibility
  	   (let ((vis-super ((@ app superior) "visibility")))
  