anchor.diff:            (when draw
               (loop for (start end object) in stroke-parts
                  for width across part-widths
  -               do (cond ((and object (eq object #\Tab))
  +               do (cond ((eql object #\Tab)
                            nil)
                           (object
                            (draw-text* stream object (+ cursor-x width)
  
positive.code:                  (incf width w)
                   (vector-push-extend width widths))))
       finally (return (values width parts widths))))
  
  (defun stroke-drawing-fn (stream view stroke cursor-x cursor-y draw)
    "Draw `stroke' to `stream' baseline-adjusted at the position (`cursor-x',
  
negative.code: 	  into parts
  	finally (return parts)))
  
  (defun calculate-stroke-width (stroke-string text-style stream x-position)
    "Calculate the width information of `stroke-string' when
  displayed with `text-style' (which must be fully specified) on
  