anchor.diff:  
       (defun reflect-force ()
         (let ((app (add-reflection (add-tilt (what)))))
  +	(with-slots () app
  +	  
  +	  )
   	app))
       
       (defun stars ()
  
positive.code:       "Reflected light on a sail app"
        (add-target (add-reflection (absorb))))
  
      (defun absorb-force ()
        (let ((app (absorb))
  	    (vel 0)
  	    (pos 0)
  	    (elapsed 0)
  	    (timefactor 10)
  	    (pause false)
  	    (time false))
  	(with-slots (sail scene mirror corners projection absorb-arrow controls render toggle-pause update animate init incidence update-tilt) app
  	  (setf
  	   toggle-pause
  	   (lambda (e)
  	     (let ((pause-html ($ "#pause")))
  	       (if pause
  		   (progn
  		     (setf pause false)
  		     (setf (@ pause-html 0 inner-h-t-m-l) "Pause"))
  		   (progn
  		     (setf pause t)
  		     (setf (@ pause-html 0 inner-h-t-m-l) "Continue")))))
  	   update
  	   (lambda ()
  	     (let* ((accel (* 5d-5 (abs (cos (* incidence (/ pi 180))))))
  
negative.code: 	((@ app camera position set) -4 -6 6)
  	app))
  
      (defun add-reflection (app)
        "Add a box showing the reflected sunlight"
        (with-slots (absorbed normal incident reflectv reflection reflect-arrow mirror corners reflect-arrow tilt-update-fn origin scene visibility) app
  