SICP ex 2.36
(define (accumulate-n op init seqs) (if (null? (car seqs)) '() (cons (accumulate op init (map (lambda (s) (car s)) seqs)) (accumulate-n op init (map (lambda (s) (cdr s)) seqs)))))
(define (accumulate-n op init seqs) (if (null? (car seqs)) '() (cons (accumulate op init (map (lambda (s) (car s)) seqs)) (accumulate-n op init (map (lambda (s) (cdr s)) seqs)))))