anchor.diff:  		       :color sdl:*red*))
   	*a*))
   
  +(defparameter *run* 't)
  +
  +(defparameter *external-quit-on-exit*
  +  (list #'(lambda () (setf *run* 'nil))))
   
   (defun sdl-main-loop ()
     ; Define key events
  
positive.code:        (update-lst (cdr *bodies*))
         (draw-bodies *bodies*)
         
         (setf *a* (append *a* (list (pos2pos (pos (cadr *bodies*))))))
         (draw-trails)
  	
        (sdl:update-display))))
  
  (defun main ()
    (sdl:with-init ()
      (sdl-init)
      (sdl-main-loop)))
  
  
  
negative.code: 
  (defun draw-body (body)
    "Draws a body to the screen"
    (sdl:draw-filled-circle
     (pos2pos (pos body)) (size body) :color (colour body)))
  
  (defun draw-bodies (bodies)
  