anchor.diff:  (defmethod compose-space ((rack vrack-pane))
     (mapc #'compose-space (sheet-children rack))
     (loop with space = (make-space-requirement 
  -		      :max-width (get-max-width (car (sheet-children rack))))
  +		      :max-width (sr-max-width (car (sheet-children rack))))
   	for child in (sheet-children rack)
   	for request = (pane-space-requirement child)
  -	sum (get-size child nil) into sum-height
  +	sum (get-pane-height child) into sum-height
   	do (setf (space-requirement-width space)
   		 (max (space-requirement-width space)
   		      (space-requirement-width request)))
  
positive.code: 		       margin-max-width margin-max-height
  		       margin-min-width margin-min-height) pane
  	    (let ((child (first (sheet-children pane))))
  	      (setf sr-width (+ margin-width (get-width child))
  		    sr-height (+ margin-height (get-height child))
  		    sr-max-width (+ margin-max-width (get-max-width child))
  		    sr-max-height (+ margin-max-height (get-max-height child))
  		    sr-min-width (+ margin-min-width (get-min-width child))
  		    sr-min-height (+ margin-min-height (get-min-height child))
  		    ))))
  	(setf space-requirement (make-space-requirement))
  	(with-slots (width height max-width max-height min-width min-height)
  
negative.code:     (loop for child in (sheet-children table) and i from 0
  	  for c = (mod i nb-children-p-l)
  	  and l = 0 then (incf l (if (zerop c) 1 0)) 
  	  when (and (zerop i) (zerop l)) sum (get-pane-width child) into sum-width
  	  when (zerop c) sum (get-pane-height child) into sum-height 
  	  do (setf (aref space-vec 0 c)
  		   (max (sr-width child) (aref space-vec 0 c))
  		   (aref space-vec 2 c)
  		   (min (sr-max-width child) (aref space-vec 2 c))
  		   (aref space-vec 4 c)
  		   (max (sr-min-width child) (aref space-vec 4 c))
  		   (aref space-vec 1 l)
  		   (max (sr-height child) (aref space-vec 1 l))
  		   (aref space-vec 3 l)
  		   (min (sr-max-height child) (aref space-vec 3 l))
  		   (aref space-vec 5 l)
  		   (max (sr-min-height child) (aref space-vec 5 l)))
  	  finally (setf (slot-value table 'sum-width) sum-width
  			(slot-value table 'sum-height) sum-height))
      (loop for i from 0 below (second (array-dimensions space-vec))
  