anchor.diff:  
   (def-grecording draw-point (point-x point-y)
     (with-transformed-position (transform point-x point-y)
  -     (values point-x point-y point-x point-y)))
  +     (values (- point-x border)
  +             (- point-y border)
  +             (+ point-x border)
  +             (+ point-y border))))
   
   (def-grecording draw-points (coord-seq)
     (with-transformed-positions (transform coord-seq)
  
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:   (let ((method-name (intern (format nil "MEDIUM-~A*" name)))
  	(class-name (intern (format nil "~A-OUTPUT-RECORD" name)))
  	(medium (gensym "MEDIUM"))
          (border 'border))
      `(progn
         (defclass ,class-name (graphics-displayed-output-record-mixin)
  	 ,(compute-class-vars args))
  