anchor.diff:  	(v-percent (/ height (space-requirement-height (pane-space-requirement box))))
   	(y 0))
       (loop for child in (sheet-children box)
  -	for request = (pane-space-requirement child)
  -	for new-width = (floor (* h-percent (space-requirement-width request)))
  -	for new-height = (floor (* v-percent (space-requirement-height request)))
  -	do (setf (sheet-region child)
  -	     (make-bounding-rectangle 0 y new-width (+ y new-height)))
  -	   (allocate-space child new-width new-height)
  -	   (incf y new-height))))
  +	  for request = (pane-space-requirement child)
  +	  for new-width = (floor (* h-percent (space-requirement-width request)))
  +	  for new-height = (floor (* v-percent (space-requirement-height request)))
  +	  do (progn (setf (sheet-region child)
  +			  (make-bounding-rectangle 0 0 new-width new-height))
  +		    (setf (sheet-transformation child)
  +			  (make-translation-transformation 0 y))
  +		    (allocate-space child new-width new-height)
  +		    (incf y new-height)))))
   
   
   ;;; HRACK-PANE class
  
positive.code:   (let ((h-percent (/ width (space-requirement-width (pane-space-requirement rack))))
  	(x 0))
      (loop for child in (sheet-children rack)
  	for request = (pane-space-requirement child)
  	for new-width = (floor (* h-percent (space-requirement-width request)))
  	do (setf (sheet-region child)
  	     (make-bounding-rectangle x 0 (+ x new-width) height))
  	   (allocate-space child new-width height)
  	   (incf x new-width))))
  
  
  ;;; VRACK-PANE class
  
negative.code: (defmethod handle-event ((pane top-level-sheet-pane) (event window-configuration-event))
    (let ((width (window-configuration-event-width event))
          (height (window-configuration-event-height event)))
      ;; avoid goint into an infinite loop by not using (setf sheet-region)
      (setf (slot-value pane 'region) (make-bounding-rectangle 0 0 width height))
      (allocate-space pane width height)))
  
  ;; SHEET 
  