anchor.diff:  	  (dolist (lt '(2 7))
   	    (with-drawing-options (stream :line-thickness lt :line-joint-shape lj :line-dashes ld)
   	      (draw-text* stream (format nil "~A ~A ~A" ld lj lt) 20 y)
  -	      (let ((x-positions '(150 300)))
  -                (declare (ignore x-positions))
  -                (draw-rectangle* stream 200 (+ 10 y) 450 (+ 35 y)
  -				   :filled nil))
  +	      (draw-rectangle* stream 200 (+ 10 y) 450 (+ 35 y)
  +                               :filled nil)
   	      (setf y (+ 40 y))))))))
   
   (define-drawing-test "04) Rectangle Clipping" (stream)
  
positive.code: 	(dolist (lt '(2 7 10))
  	  (with-drawing-options (stream :line-thickness lt :line-dashes ld)
  	    (draw-text* stream (format nil "~A ~A" ld lt) 20 y)
  	    (let ((x-positions '(150 300)))
                (declare (ignore x-positions))
  	      (draw-ellipse* stream 150 (+ 10 y) 0 30 50 0
  			     :filled nil)
  	      (draw-ellipse* stream 270 (+ 10 y) 0 30 50 0 :start-angle (/ pi 2) :end-angle pi
  			     :filled nil)
  	      (draw-ellipse* stream 390 (+ 10 y) 0 30 50 0 :start-angle (- (/ pi 2)) :end-angle pi
  			     :filled nil))
  	    (setf y (+ 80 y)))))))
  
  (define-drawing-test "05) Ellipse Clipping" (stream)
  
negative.code: 	(dolist (lt '(2 7 10))
  	  (with-drawing-options (stream :line-thickness lt :line-dashes ld)
  	    (draw-text* stream (format nil "~A ~A" ld lt) 20 y)
  	    (draw-circle* stream 200 (+ 10 y) 30
                            :filled nil)
              (draw-circle* stream 290 (+ 10 y) 30 :start-angle (/ pi 2) :end-angle pi
                            :filled nil)
              (draw-circle* stream 380 (+ 10 y) 30 :start-angle (- (/ pi 2)) :end-angle pi
                            :filled nil)
  	    (setf y (+ 80 y)))))))
  
  (define-drawing-test "06) Circle Clipping" (stream)
  