再帰で (define (eratosthenes n) (define (recur lis) (if (null? lis) '() (cons (car lis) (recur (filter (lambda (x) (not (= (modulo x (car lis)) 0))) lis))))) (recur (iota (- (round n) 1) 2))) 繰り返しで (define (eratosthenes n) (define (it…

(define (deriv exp var) (cond ((number? exp) 0) ((variable? exp) (if (same-variable? exp var) 1 0)) (else (get 'deriv (operator exp)) (operands exp) var))) (define (operator exp) (car exp)) (define (operands exp) (cdr exp)) ;; a 元のプログ…