anchor.diff:    =>
     (assert (goal-is-to (action on) (argument-1 ladder))))
   
  +#+ignore
   (defrule grab-object-from-ladder
     (?goal (goal-is-to (action hold) (argument-1 ?name)))
     (?thing (thing (name ?name) (location ?place) 
  
positive.code: ;;; Description: The "Monkey And Bananas" sample implementation, a common AI
  ;;; planning problem. The monkey's objective is to find and eat some bananas.
  
  ;;; $Id: mab.lisp,v 1.9 2001/01/21 00:32:35 youngde Exp $
  
  (in-package :lisa)
  
  
negative.code:   =>
    (format t "Monkey eats the ~A.~%" ?name)
    (modify ?monkey (holding blank))
    (retract ?goal)
    (retract ?thing))
  
  ;;; startup rule...
  
  