崔添翼 § 翼若垂天之云

?View Code SCHEME;; 2.1 (define (make-rat n d) (if (< d 0) (make-rat (- n) (- d)) (cons n d)))   ;; 2.2 (define (make-point x y) (cons x y)) (define (x-point p) (car p)) (define (y-point p) (cdr p)) (define (make-segment start end) (cons start end)) (define (start-segment s) (car s)) (define (end-segment s) [...]