1 665c255d 2023-08-04 jrmu (define (add-interval x y)
 2 665c255d 2023-08-04 jrmu   (make-interval (+ (lower-bound x) (lower-bound y))
 3 665c255d 2023-08-04 jrmu 		 (+ (upper-bound x) (upper-bound y))))
 4 665c255d 2023-08-04 jrmu (define (mul-interval x y)
 5 665c255d 2023-08-04 jrmu   (let ((p1 (* (lower-bound x) (lower-bound y)))
 6 665c255d 2023-08-04 jrmu 	(p2 (* (lower-bound x) (upper-bound y)))
 7 665c255d 2023-08-04 jrmu 	(p3 (* (upper-bound x) (lower-bound y)))
 8 665c255d 2023-08-04 jrmu 	(p4 (* (upper-bound x) (upper-bound y))))
 9 665c255d 2023-08-04 jrmu     (make-interval (min p1 p2 p3 p4)
10 665c255d 2023-08-04 jrmu 		   (max p1 p2 p3 p4))))
11 665c255d 2023-08-04 jrmu 
12 665c255d 2023-08-04 jrmu (define (div-interval x y)
13 665c255d 2023-08-04 jrmu   (mul-interval x
14 665c255d 2023-08-04 jrmu 		(make-interval (/ 1.0 (upper-bound y))
15 665c255d 2023-08-04 jrmu 			       (/ 1.0 (lower-bound y)))))
16 665c255d 2023-08-04 jrmu 
17 665c255d 2023-08-04 jrmu (define (make-interval a b)
18 665c255d 2023-08-04 jrmu   (cons a b))
19 665c255d 2023-08-04 jrmu (define (upper-bound x)
20 665c255d 2023-08-04 jrmu   (cdr x))
21 665c255d 2023-08-04 jrmu (define (lower-bound x)
22 665c255d 2023-08-04 jrmu   (car x))
23 665c255d 2023-08-04 jrmu 
24 665c255d 2023-08-04 jrmu