anchor.diff:  (defclass stream-output-history-mixin ()
     ())
   
  -(defclass standard-sequence-output-history (standard-sequence-output-record stream-output-history-mixin)
  +(defclass standard-sequence-output-history
  +    (standard-sequence-output-record stream-output-history-mixin)
     ())
   
  -(defclass standard-tree-output-history (standard-tree-output-record stream-output-history-mixin)
  +(defclass standard-tree-output-history
  +    (standard-tree-output-record stream-output-history-mixin)
     ())
   
   
positive.code: ;;; Graphics and text recording classes
  
  (eval-when (:compile-toplevel :load-toplevel :execute)
    
    (defun compute-class-vars (names)
      (cons (list 'stream :initarg :stream)
  	  (loop for name in names
  		collecting (list name :initarg (intern (symbol-name name) :keyword)))))
  
    (defun compute-arg-list (names)
      (loop for name in names
  	  nconcing (list (intern (symbol-name name) :keyword) name)))
    )
  
  (defun make-merged-medium (sheet ink clip transform line-style text-style)
    (let ((medium (make-medium (port sheet) sheet)))
      (setf (medium-ink medium) ink)
      ;; First set transformation, then clipping region!
      (setf (medium-transformation medium) transform)
      (setf (medium-clipping-region medium) clip)
      (setf (medium-line-style medium) line-style)
      (setf (medium-text-style medium) text-style)
      medium))
  
  (defmacro def-grecording (name (&rest args) &body body)
    (let ((method-name (intern (format nil "MEDIUM-~A*" name)))
  	(class-name (intern (format nil "~A-OUTPUT-RECORD" name)))
  	(old-medium (gensym))
  	(new-medium (gensym))
  	(border (gensym)))
      `(progn
         (defclass ,class-name (graphics-displayed-output-record-mixin)
  	 ,(compute-class-vars args))
  
negative.code: ;;; -*- Mode: Lisp; Package: CLIM-INTERNALS -*-
  
  ;;;  (c) copyright 1998,1999,2000,2001 by Michael McDonald (mikemac@mikemac.com)
  ;;;  (c) copyright 2000 by
  ;;;           Robert Strandh (strandh@labri.u-bordeaux.fr)
  ;;;  (c) copyright 2001 by
  ;;;           Arnaud Rouanet (rouanet@emi.u-bordeaux.fr)
  ;;;           Lionel Salabartan (salabart@emi.u-bordeaux.fr)
  ;;;  (c) copyright 2001, 2002 by Alexey Dejneka (adejneka@comail.ru)
  
  ;;; This library is free software; you can redistribute it and/or
  ;;; modify it under the terms of the GNU Library General Public
  