(define (triples n) (let ((1..n (enumerate-interval 1 n))) (flatmap (lambda (i) (flatmap (lambda (j) (map (lambda (k) (list i j k) (filter (lambda (x) (and (not (= i x)) (not (= j x)))) 1..n)) (filter (lambda (x) (not (= i x))) 1..n)) 1..n…

(define (unique-pairs n) (flatmap (lambda (i) (map (lambda (j) (list i j)) (enumerate-interval 1 (- i 1)))) (enumerate-interval 1 n))) (define (prime-sum-pairs n) (map make-pair-sum (filter prime-sum? (unique-pairs n)))) flatmap 手続きは H…