[CODE]
(define (smallest-divisor n) (find-divisor n 2)) (define (find-divisor n test-divisor) (cond ((> (square test-divisor) n) n) ((divides? test-divisor n) test-divisor) (else (find-divisor n (+ test-divisor 1))))) (define (divides? a b) (= (remainder b a) 0)) (define (prime? n) (= n (smallest-divisor n))) (define (square x) (* x x)) [/CODE]

실행 결과
> (smallest-divisor 199)
199
> (smallest-divisor 1999)
1999
> (smallest-divisor 19999)
7