From: Tom Kramer
Subject: April foolery
Date: Mon, 01 Apr 1991 19:19:13 +0000
Message-ID: <985@graceland.cme.nist.gov>

What does this do? How does it work? How long does it take?

(defun bleep (arg)
  (cond ((eq arg 1) 1)
        ((numberp arg)
         (bleep (bleep (list arg (list (list (- arg 1)))))))
        ((and (numberp (car arg)) (zerop (car arg)))
         nil)
        ((and (numberp (car arg)) (numberp (cadr arg)))
         (apply #'+ (mapcar #'(lambda (zz) (bleep (cdr arg))) arg)))
        ((and (numberp (car arg)) (null (cdr arg)))
         1)
        ((numberp (car arg))
         (cons (cadr arg) (bleep (list (1- (car arg)) (cadr arg)))))
        ((listp (caar arg))
         (bleep (mapcar #'bleep arg)))
        ((not (eq (caar arg) 1))
         (bleep (bleep (list (bleep (caar arg))
                             (list (list (- (caar arg) 1)))))))
        (t 1)))