;; P05 (*) Reverse a list
(defun my-reverse (lst)
  (defun my-reverse-rec (lst res)
    (cond
     ((eq lst '()) res)
     (t
      (my-reverse-rec (cdr lst) (cons (car lst) res)))))
  (my-reverse-rec lst '()))

(my-reverse '(a b c)) ; '(c b a)