1 (define wave2 (besides wave (flip-vert wave)))
2 (define wave4 (below wave2 wave2))
3 (define (flipped-pairs painter)
4   (let ((painter2 (besides painter (flip-vert painter))))
5     (below painter2 painter2)))
6 (define wave4 (flipped-pairs wave))
7 (define (right-split painter n)
8   (if (= n 0)
9       painter
10       (let ((smaller (right-split painter (- n 1))))
11 	(beside painter (below smaller smaller)))))
12 
13 (define (corner-split painter n)
14   (if (= n 0)
15       painter
16       (let ((up (up-split painter (- n 1)))
17 	    (right (right-split painter (- n 1))))
18 	(let ((top-left (beside up up))
19 	      (bottom-right (below right right))
20 	      (corner (corner-split painter (- n 1))))
21 	  (beside (below painter top-left)
22 		  (below bottom-right corner))))))
23 
24 (define (square-limit painter n)
25   (let ((quarter (corner-split painter n)))
26     (let ((half (beside (flip-horiz quarter) quarter)))
27       (below (flip-vert half) half))))
28 (define (up-split painter n)
29   (if (= n 0)
30       painter
31       (let ((up (up-split painter (- n 1))))
32 	(below painter (beside up up)))))