anchor.diff:    (multiple-value-bind (font size)
         (text-style->postscript-font
          (merge-text-styles text-style
  -                          (medium-text-style medium)))
  +                          (medium-merged-text-style medium)))
       (text-size-in-font font size
                          string start (or end (length string)))))
  
positive.code:         (*transformation* (sheet-native-transformation (medium-sheet medium)))
          (radius (format-postscript-number (/ (medium-line-thickness medium) 2))))
      (postscript-actualize-graphics-state stream medium :color)
      (with-graphics-state (medium) ; FIXME: this is because of setlinewidth below
        (format stream "newpath~%")
        (write-coordinates stream x y)
        (format stream "~A 0 360 arc~%" radius)
        (format stream "0 setlinewidth~%")
        (format stream "fill~%"))))
  
  (defmethod medium-draw-points* ((medium postscript-medium) coord-seq)
    (let ((stream (postscript-medium-file-stream medium))
          (*transformation* (sheet-native-transformation (medium-sheet medium)))
          (radius (format-postscript-angle (/ (medium-line-thickness medium) 2))))
      (postscript-actualize-graphics-state stream medium :color)
      (with-graphics-state (medium) ; FIXME: this is because of setlinewidth below
        (format stream "0 setlinewidth~%")
        (map-repeated-sequence 'nil 2
                               (lambda (x y)
                                 (format stream "newpath~%")
                                 (write-coordinates stream x y)
                                 (format stream "~A 0 360 arc~%" radius)
                                 (format stream "fill~%"))
                               coord-seq))))
  
  (defmethod medium-draw-line* ((medium postscript-medium) x1 y1 x2 y2)
    (let ((stream (postscript-medium-file-stream medium))
  
negative.code: 
  (defconstant +normal-line-width+ (/ 2.0 3.0))
  
  (defun line-style-scale (line-style)
    (let ((unit (line-style-unit line-style)))
      (ecase unit
        (:normal +normal-line-width+)
        (:point 1)
        (:coordinate (error ":COORDINATE line unit not implemented.")))))
  
  (defmethod line-style-effective-thickness
      (line-style (medium postscript-medium))
    (* (line-style-thickness line-style)
       (line-style-scale line-style)))
  
  (defun medium-line-thickness (medium)
    (line-style-effective-thickness (medium-line-style medium) medium))
  
  (defmethod postscript-set-graphics-state (stream medium
                                            (kind (eql :line-style)))
    (let* ((line-style (medium-line-style medium))
           (scale (line-style-scale line-style)))
      (format stream "~D setlinewidth ~A setlinejoin ~A setlinecap~%"
              (format-postscript-number
               (* scale (line-style-thickness line-style)))
  