anchor.diff:  ;;; Fall-through Methods For Multiple Objects Drawing Functions
   
   (defmethod medium-draw-points* ((medium basic-medium) coord-seq)
  -  ;; WRONG! 
     (let ((tr (invert-transformation (medium-transformation medium))))
       (with-transformed-positions (tr coord-seq)
  -      (loop for (x y) on coord-seq by #'cddr
  -            do (medium-draw-point* medium x y)))))
  +      (map-repeated-sequence nil 2
  +                             (lambda (x y)
  +                               (medium-draw-point* medium x y))
  +                             coord-seq))))
   
   (defmethod medium-draw-lines* ((medium basic-medium) position-seq)
  -  ;; WRONG! 
     (let ((tr (invert-transformation (medium-transformation medium))))
       (with-transformed-positions (tr position-seq)
  -      (loop for (x1 y1 x2 y2) on position-seq by #'cddddr
  -            do (medium-draw-line* medium x1 y1 x2 y2)))))
  +      (map-repeated-sequence nil 4
  +                             (lambda (x1 y1 x2 y2)
  +                               (medium-draw-line* medium x1 y1 x2 y2))
  +                             position-seq))))
   
   (defmethod medium-draw-rectangles* ((medium basic-medium) coord-seq filled)
  -  ;; WRONG! 
     (let ((tr (invert-transformation (medium-transformation medium))))
       (with-transformed-positions (tr coord-seq)
  -      (loop for (x1 y1 x2 y2) on coord-seq by #'cddddr
  -            do (medium-draw-rectangle* medium x1 y1 x2 y2 filled)))))
  +      (map-repeated-sequence nil 4
  +                             (lambda (x1 y1 x2 y2)
  +                               (medium-draw-rectangle* medium
  +                                                       x1 y1 x2 y2
  +                                                       filled))
  +                             coord-seq))))
   
    
  
positive.code:   (declare (type symbol medium))
    (when (eq medium t)
      (setq medium '*standard-output*))
    `(flet ((continuation (,medium)
  	    ,@body))
       (declare (dynamic-extent #'continuation))
       (invoke-with-text-style ,medium #'continuation
                               (make-text-style ,family nil nil))))
  
  (defmacro with-text-face ((medium face) &body body)
    (declare (type symbol medium))
    (when (eq medium t)
      (setq medium '*standard-output*))
    `(flet ((continuation (,medium)
  	    ,@body))
       (declare (dynamic-extent #'continuation))
       (invoke-with-text-style ,medium #'continuation
                               (make-text-style nil ,face nil))))
  
  (defmacro with-text-size ((medium size) &body body)
    (declare (type symbol medium))
    (when (eq medium t) (setq medium '*standard-output*))
    `(flet ((continuation (,medium)
  	    ,@body))
       (declare (dynamic-extent #'continuation))
       (invoke-with-text-style ,medium #'continuation
                               (make-text-style nil nil ,size))))
  
  
  
negative.code: ;; - Why is (EQ (MAKE-TEXT-STYLE NIL NIL 10) (MAKE-TEXT-STYLE NIL NIL 10.0005)) = T?
  ;;   Does it matter?
  ;; - Don't we want a weak hash-table for *TEXT-STYLE-HASH-TABLE*
  ;;
  ;; --GB 2002-02-26
  
  