|
; (define (make-rat n d) (cons n d))
|
|
(define (numer x) (car x))
|
|
(define (denom x) (cdr x))
|
|
|
|
(define (make-rat n d)
|
|
(cond ((and (> n 0) (> d 0))
|
|
(cons n d))
|
|
((and (< n 0) (< d 0))
|
|
(cons (* n -1) (* d -1)))
|
|
((and (< n 0) (> d 0))
|
|
(cons n d))
|
|
(else
|
|
(cons (* n -1) (* d -1)))))
|
|
|