kiwi's garden

用的DrRacket平台   #lang racket (* 5 6) (define (square x) (* x x)) (define (sum-of-squares x y)    (+ (square x) (square y))) compound procedure cond (if ) (define (ab

compound structure: Pair use con to generate a pair (define x (cons 1 2)) Representing rational numbers (define (make-rat n d) (cons n d)) (define (numer x) (car x)) (define (denom x) (cd