anchor.diff:                                        (left-tokens add-token))
     (loop for right-token being the hash-value 
         of (join-node-right-memory self)
  -      do (when (and (test-tokens self left-tokens right-token)
  -                    (= (token-increment-exists-counter left-tokens) 1))
  +      do (when (test-tokens self left-tokens right-token)
  +           (token-increment-exists-counter left-tokens)
              (pass-tokens-to-successor 
               self (combine-tokens left-tokens right-token)))))
   
  
positive.code: ;;; File: node2-exists.lisp
  ;;; Description:
  
  ;;; $Id: node2-exists.lisp,v 1.1 2002/11/18 15:59:33 youngde Exp $
  
  (in-package "LISA")
  
  
negative.code:                                       (left-tokens remove-token))
    (loop for right-token being the hash-value 
        of (join-node-right-memory self)
        do (when (test-tokens self left-tokens right-token)
             (pass-tokens-to-successor 
              self (combine-tokens left-tokens right-token)))))
  
  