anchor.diff:    (with-tree-iterator (key left-token tree)
       (when (or (not (has-tests-p self))
                 (run-tests self left-token (get-top-fact right-token)))
  -      (pass-new-token self right-token left-token)))
  +      (pass-token-from-left self right-token left-token)))
     (values nil))
  
positive.code:       (increment-negation-count token)))
    (values nil))
  
  (defmethod pass-new-token ((self node2-not) (right-token clear-token) left-token)
    (when (= (decrement-negation-count left-token) 0)
      (with-accessors ((engine get-engine)) self
        (let ((token (make-derived-token (class-of left-token)
  
negative.code: ;;; File: node2-not.lisp
  ;;; Description: Specialized two-input node for negated patterns.
  
  ;;; $Id: node2-not.lisp,v 1.4 2000/12/12 00:09:32 youngde Exp $
  
  (in-package :lisa)
  
  