;; (define map (lambda (f xs)
;; (let ((accmap (lambda (acc xs)
;; (if (eq xs nil)
;; acc
;; (accmap (cons (f (car xs)) acc) (cdr xs))))))
;; (reverse (accmap nil xs)))))
(check (eq (map (lambda (x) (+ x 1)) (list 1 2 3 4 5 6)) (list 2 3 4 5 6 7)))