anchor.diff:  (define-graph-type :digraph digraph-graph-output-record)
   
   ;;;; Entry
  +(defun format-graph-from-root (root-object &rest other-args)
  +  (apply #'format-graph-from-roots (list root-object) other-args))
   
   (defun format-graph-from-roots (root-objects object-printer inferior-producer
  -                                &rest graph-options
  +                                &rest rest-args
                                   &key stream orientation cutoff-depth
                                        merge-duplicates duplicate-key duplicate-test
                                        generation-separation
  
positive.code:    (object
      :initarg :object
      :reader graph-node-object)
     ;; internal slots for the graph layout algorithmn
     (minor-size
      :initform nil
      :accessor graph-node-minor-size
  
negative.code: ;;;     Title: Graph Formatting
  ;;;   Created: 2002-08-13
  ;;;   License: LGPL (See file COPYING for details).
  ;;;       $Id: graph-formatting.lisp,v 1.21 2007-09-16 22:39:22 rgoldman Exp $
  ;;; ---------------------------------------------------------------------------
  
  ;;;  (c) copyright 2002 by Gilbert Baumann
  