anchor.diff:  	;; Move the camera
   	((@ 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 update-tilt origin scene visibility sail) app
  
positive.code: 	 corners (corners mirror)
  	 projection (projection corners)
  	 incident (incident)
  	 absorb-arrow (new (3fn *arrow-helper incident origin 10 0xffff00))
  	 visibility
  	 (let ((visibility-super ((@ app superior) "visibility")))
  	   (lambda (bool)
  
negative.code: (define-easy-handler (lib-js :uri "/js/lib.js") ()
    (setf (content-type*) "text/javascript")
    (ps
      
      (defmacro 3fn (fn &rest args)
        `((@ *three* ,fn) ,@args))
      
      (defun toggle-div (div-id)
        ((@ ($ (+ "#" div-id)) toggle)))
      
      (setf (@ *function prototype method)
  	  (lambda (name func)
  	    (when (not (elt (@ this prototype) name))
  	      (setf (elt (@ this prototype) name) func)
  	      this)))
      
      ((@ *object method) "superior"
       (lambda (name)
         (let* ((that this)
  