anchor.diff:        (with-slots (start-x start-y end-x end-y x1 y1 x2 y2
                      initial-x1 initial-y1) record
   	  (multiple-value-bind (cx cy) (stream-cursor-position stream)
  -	    (setq start-x cx
  -		  start-y (+ cy (stream-vertical-spacing stream))
  +	    (setq start-x (coordinate cx)
  +		  start-y (coordinate (+ cy (stream-vertical-spacing stream)))
   		  end-x start-x
   		  end-y start-y
   		  x1 start-x
  
positive.code: 	    (setf (medium-sheet new-medium) stream)
              (setf (medium-transformation new-medium)
                     (make-translation-transformation
                      x-offset y-offset))
  	    (loop for y = (+ start-y baseline)
  		  for (x text-style string) in strings
  		  do (setf (medium-text-style new-medium) text-style)
  		     (draw-text* (sheet-medium stream) string x y
  				 :text-style text-style :clipping-region #-nil +everywhere+ #+nil(untransform-region (medium-transformation new-medium) region)))
  	    (if wrapped
  		(draw-rectangle* (sheet-medium stream)
  				 (+ wrapped 0) start-y (+ wrapped 4) (+ start-y max-height)
  				 :ink +foreground-ink+
  				 :filled t)))
  	(setf (sheet-medium stream) old-medium)))))
  
  (defmethod output-record-start-cursor-position ((record text-displayed-output-record))
    (with-slots (start-x start-y) record
  
negative.code:   (
     ))
  
  ;;; 16.4.1 The Output Recording Stream Protocol
  (defgeneric stream-recording-p (stream))
  (defgeneric (setf stream-recording-p) (recording-p stream))
  (defgeneric stream-drawing-p (stream))
  (defgeneric (setf stream-drawing-p) (drawing-p stream))
  (defgeneric stream-output-history (stream))
  (defgeneric stream-current-output-record (stream))
  (defgeneric (setf stream-current-output-record) (record stream))
  (defgeneric stream-add-output-record (stream record))
  (defgeneric stream-replay (stream &optional region))
  (defgeneric erase-output-record (record stream &optional (errorp t)))
  (defgeneric copy-textual-output-history (window stream &optional region record))
  
  ;;; 16.4.3 Text Output Recording
  (defgeneric stream-text-output-record (stream text-style))
  (defgeneric stream-close-text-output-record (stream))
  (defgeneric stream-add-character-output
    (stream character text-style width height baseline))
  (defgeneric stream-add-string-output
    (stream string start end text-style width height baseline))
  
  ;;; Methods
  (defmethod initialize-instance :after ((stream output-recording-stream) &rest args)
    (declare (ignore args))
    (setf (stream-current-output-record stream) (stream-output-history stream)))
  