anchor.diff:        ,@body
         (format ,gstream "grestore~%"))))
   
  +(defun format-postscript-number (number)
  +  (if (not (integerp number))
  +      (coerce number 'single-float)
  +      number))
  +
   (defmethod medium-draw-point* ((medium postscript-medium) x y)
     (let ((stream (postscript-medium-file-stream medium)))
       (with-graphics-state (stream)
  -      (format stream "~,15G ~,15G ~,15G 0 360 arc~%"
  -	      x y (/ (line-style-thickness (medium-line-style medium)) 2))
  +      (format stream "~A ~A ~A 0 360 arc~%"
  +	      (format-postscript-number x) (format-postscript-number y)
  +              (format-postscript-number
  +               (/ (line-style-thickness (medium-line-style medium)) 2)))
         (format stream "0 setlinewidth~%")
         (postscript-color stream medium)
         (format stream "fill~%"))))
  
positive.code:       (loop with points = (apply #'vector coord-seq)
              for i below (length coord-seq) by 4
              do
              (format stream "~,15G ~,15G moveto ~,15G ~,15G lineto~%"
                      (aref points i) (aref points (1+ i))
                      (aref points (+ i 2)) (aref points (+ i 3)))
              finally (format stream "stroke~%")))))
  
  (defmethod medium-draw-polygon* ((medium postscript-medium) coord-seq closed filled)
    (assert (evenp (length coord-seq)))
    (let ((stream (postscript-medium-file-stream medium)))
      (with-graphics-state (stream)
        (format stream "~,15G ~,15G moveto~%" (car coord-seq) (cadr coord-seq))
        (loop for (x y) on (cddr coord-seq) by #'cddr
              do (format stream "~,15G ~,15G lineto~%" x y)
              finally (format stream "~%"))
        (when closed
          (format stream "closepath~%"))
  
negative.code: (defmethod medium-draw-rectangle* ((medium postscript-medium) x1 y1 x2 y2 filled)
    (let ((stream (postscript-medium-file-stream medium)))
      (with-graphics-state (stream)
        (format stream "~A ~A moveto ~A ~A lineto ~A ~A lineto ~A ~A lineto~%"
                (format-postscript-number x1) (format-postscript-number y1)
                (format-postscript-number x2) (format-postscript-number y1)
                (format-postscript-number x2) (format-postscript-number y2)
                (format-postscript-number x1) (format-postscript-number y2))
        (format stream "closepath~%")
        (postscript-line-style-and-color stream medium)
        (format stream (if filled
  