anchor.diff:             (merge-root-node (new-root)
                (let ((existing-root
                       (find-root-node to-rete new-root)))
  -               (if (null existing-root)
  -                   (add-new-root to-rete new-root)
  -                 (merge-successors
  -                  existing-root (shared-node-all-successors new-root))))))
  +               (cond ((null existing-root)
  +                      (add-new-root to-rete new-root))
  +                     (t
  +                      (add-node-set t existing-root)
  +                      (merge-successors
  +                       existing-root 
  +                       (shared-node-all-successors new-root)))))))
       (let ((*node-set* (list)))
         (loop for new-root being the hash-value
             of (rete-roots from-rete)
  
positive.code:     (increment-use-count parent))
    (push (make-node-pair node parent) *node-set*))
  
  (defmethod add-node-set (parent node &optional count-p)
    (declare (ignore parent node count-p))
    nil)
  
  (defun merge-networks (from-rete to-rete)
    (labels ((find-root-node (network node)
  
negative.code: ;;; File: network-ops.lisp
  ;;; Description:
  
  ;;; $Id: network-ops.lisp,v 1.15 2002/10/08 18:54:45 youngde Exp $
  
  (in-package "LISA")
  
  