anchor.diff:  ;;; File: network-ops.lisp
   ;;; Description:
   
  -;;; $Id: network-ops.lisp,v 1.13 2002/10/08 18:17:27 youngde Exp $
  +;;; $Id: network-ops.lisp,v 1.14 2002/10/08 18:34:31 youngde Exp $
   
   (in-package "LISA")
   
  
positive.code:            (merge-successors (parent successors)
               (if (endp successors) parent
                 (let* ((new-successor (first successors))
                        (successor-node (successor-node new-successor))
                        (existing-successor 
                         (successor-exists-p parent successor-node)))
                   (cond ((null existing-successor)
                          (add-successor parent successor-node
                                         (successor-connector new-successor))
                          (add-node-set parent successor-node))
                         (t
                          (add-node-set parent successor-node t)
                          (merge-successors 
                           (successor-node existing-successor)
                           (shared-node-all-successors successor-node))))
                   (merge-successors parent (rest successors)))))
             (merge-root-node (new-root)
               (let ((existing-root
  
negative.code:                  (remove-nodes (rest nodes))))))
      (remove-nodes (rule-node-list rule))))
  
  (defmethod find-existing-successor ((parent shared-node) (node node1))
    (gethash (node1-test node) (shared-node-successors parent)))
  
  (defmethod find-existing-successor (parent node)
    (declare (ignore parent node))
    nil)
  
  