练习2.33-2.36 exercise 2.33
(define (accumulate-n op init seqs) (if (null? (car seqs)) nil (cons (accumulate op init (map car seqs)) (accumulate-n op init (map cdr seqs)))))(define s (list (list 1 2 3) (list 4 5 6) (list 7 8 9) (list 10 11 12)))
