anchor.diff:  	  
   	  )
   	app))
  -
  +    
       (defun add-booms (app)
         "Add booms"
         (with-slots (sail booms render) app
  
positive.code: 	(setf normal (normal sail)
  	      reflectv (reflectv incident normal)
  	      reflection (reflection corners reflectv)
  	      reflect-arrow (new (3fn *arrow-helper reflectv origin 10 0xffff00))
  	      visibility
  	      (let ((visibility-super ((@ app superior) "visibility")))
  		(lambda (bool)
  		  (funcall visibility-super bool)
  		  (setf (@ reflection visible) bool
  			(@ reflect-arrow visible) bool)))
  	      update-tilt
  	      (let ((tilt-super ((@ app superior) "updateTilt"))) 
  		(lambda ()
  
negative.code: 	;; 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
  