anchor.diff:                                           :start start :end end
                                            :text-style text-style))
                (eol-action (stream-end-of-line-action stream))
  -             (eol-p (and right-margin (> (+ cx width) right-margin))))
  +             (eol-p (> (+ cx width) right-margin)))
           (when (or (null eol-p) (member eol-action '(:allow :scroll)))
             (stream-write-output stream string nil start end)
             (incf cx width)
             (setf (cursor-position (stream-text-cursor stream)) (values cx cy))
  -          (when (and right-margin
  -                     (> (+ cx width) right-margin)
  +          (when (and (> (+ cx width) right-margin)
                        (eql eol-action :scroll))
               (multiple-value-bind (tx ty)
                   (bounding-rectangle-position (sheet-region stream))
  
positive.code:        (declare (dynamic-extent #',cont))
         (invoke-with-room-for-graphics #',cont ,stream ,@arguments))))
  
  (defmacro with-end-of-line-action ((stream action) &body body)
    (when (eq stream t)
      (setq stream '*standard-output*))
    (check-type stream symbol)
    `(letf (((stream-end-of-line-action ,stream) ,action))
       ,@body))
  
  (defmacro with-end-of-page-action ((stream action) &body body)
    (when (eq stream t)
      (setq stream '*standard-output*))
    (check-type stream symbol)
    `(letf (((stream-end-of-page-action ,stream) ,action))
       ,@body))
  
  (defmethod beep (&optional medium)
    (if medium
        (medium-beep medium)
  
negative.code:         (let ((sheet (or (pane-viewport stream) stream)))
            ;; Sheet region may not be bound (ie in PostScript backend).
            (if (region-equal (sheet-region sheet) +everywhere+)
                (* 80 (text-style-width *default-text-style* stream))
                (bounding-rectangle-width sheet))))))
  
  (defgeneric stream-effective-bottom-margin (stream)
    (:documentation "Absolute position of the bottom margin in stream coordinates.")
    (:method ((stream standard-extended-output-stream))
      (let ((sheet (or (pane-viewport stream) stream)))
        ;; Sheet region may not be bound (ie in PostScript backend).
        (if (region-equal (sheet-region sheet) +everywhere+)
            (* 43 (text-style-height *default-text-style* stream))
            (bounding-rectangle-height stream)))))
  
  (defmethod initialize-instance :after
      ((stream standard-extended-output-stream) &rest args)
  