;; SRFI 1: リスト ライブラリ http://www.chino-js.com/tech/srfi/srfi-1/srfi-1.html#zip

(use srfi-1)

(unfold-right null? car cdr (fold cons '() '(1 2 3 4 5)))
;; (1 2 3 4 5)

(let ((seq (cut <> cons '() '(1 2 3 4 5)))
      (rev (cut <> null? car cdr <>)))
  (values (rev unfold-right (seq fold))
          (rev unfold (seq fold-right))))
;; (1 2 3 4 5)
;; (1 2 3 4 5)


(let ((seq (cut <> cons '() '(1 2 3 4 5)))
      (rev (cut <> null? car cdr <>)))
  (equal? (rev unfold-right (seq fold))
          (rev unfold (seq fold-right))))
;; #t