COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	(defun ack (x y) (cond
C00003 ENDMK
C⊗;
(defun ack (x y) (cond
  ((zerop x) (add1 y))
  ((zerop y) (ack (sub1 x) 1))
  (t (ack (sub1 x) (ack x (sub1 y))))))

(defun rev (x y) (cond
  ((null x) y)
  (t (rev (cdr x) (cons (car x) y)))))

(defun lin (l r) (cond
  ((null l) r)
  ((atom l) (cons l r))
  (t (lin (car l) (lin (cdr l) r)))))

(defun alt (l m n) (cond
  ((null l) nil)
  ((= m 1) (cons (car l) (alt (cdr l) n n)))
  (t (alt (cdr l) (1- m) n))))

(defun lastl (l) (cond
  ((cdr l) (lastl (cdr l)))
  ((atom (car l)) (car l))
  (t (lastl (car l)))))