anchor.diff:     (holding :initarg :holding
               :initform 'nothing)))
   
  -(defclass thing ()
  +(defclass thing (mab-fundamental)
     ((name :initarg :name)
      (location :initarg :location)
      (on-top-of :initarg :on-top-of
  
positive.code:   (monkey (satisfied t) (:object ?monkey))
    =>
    (format t "Monkey is satisfied: ~S~%" ?monkey))
  
  ;;; startup rule...
  
  
negative.code: ;;; introspection. The last form illustrates how one might limit the slots of
  ;;; interest by specifying them explicitly...
  
  (defimport mab-fundamental (lisa-user::mab-fundamental) ())
  
  (defimport monkey (lisa-user::monkey (mab-fundamental)) ())
  
  (defimport thing (lisa-user::thing (mab-fundamental)) ())
  
  (defimport chest (lisa-user::chest (mab-fundamental)) ())
  
  (defimport goal-is-to (lisa-user::goal-is-to (mab-fundamental))
    (action argument-1 argument-2))
  
  ;;;(watch :activations)
  