anchor.diff:  		      stream ink clipping-region transform
   		      line-style text-style
   		      ,@args) graphic
  -           (let ((,border (1+ (/ (line-style-thickness line-style) 2))))
  -             (multiple-value-bind (lf tp rt bt) (progn ,@body)
  -               (setq x1 (- lf ,border)
  -                     y1 (- tp ,border)
  -                     x2 (+ rt ,border)
  -                     y2 (+ bt ,border))))
  +           (let ((,border (/ (line-style-effective-thickness
  +                              line-style (sheet-medium stream))
  +                             2)))
  +             (declare (ignorable ,border))
  +             (multiple-value-setq (x1 y1 x2 y2) (progn ,@body)))
              (setf x x1
                    y y1
                    initial-x1 x1
  
positive.code:            minimize y into min-y
             maximize x into max-x
             maximize y into max-y
             finally (return (values min-x min-y max-x max-y)))))
  
  (def-grecording draw-polygon (coord-seq closed filled)
    ;; FIXME !!!
  
negative.code:            minimize y into min-y
             maximize x into max-x
             maximize y into max-y
             finally (return (values (- min-x border)
                                     (- min-y border)
                                     (+ max-x border)
                                     (+ max-y border))))))
  
  (def-grecording draw-line (point-x1 point-y1 point-x2 point-y2)
    (with-transformed-position (transform point-x1 point-y1)
      (with-transformed-position (transform point-x2 point-y2)
        (values (- (min point-x1 point-x2) border)
                (- (min point-y1 point-y2) border)
                (+ (max point-x1 point-x2) border)
                (+ (max point-y1 point-y2) border)))))
  
  (def-grecording draw-lines (coord-seq)
    (with-transformed-positions (transform coord-seq)
  