gistfile1.el

(defmacro message-to-poland (obj &optional (mesg nil mesg-sup?) &rest arg)
  (cond (arg `(,mesg ,obj (message-to-poland ,@arg)))
        (mesg-sup? `(,mesg ,obj))
        ('T `,obj)))


(set-macro-character #\[ (lambda (stream char)
                           (declare (ignore char))
                           `(message-to-poland ,@(read-delimited-list #\] stream 'T))))

(set-macro-character #\] (get-macro-character #\) nil))


;;
(defun tarai (x y z)
  (cond ([x > y]
         (tarai
          (tarai [x - 1] y z)
          (tarai [y - 1] z x)
          (tarai [z - 1] x y) ))
        (t y) ))