; Copyright (C) 2001  Georgia Institute of Technology

; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2 of the License, or
; (at your option) any later version.

; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.

; You should have received a copy of the GNU General Public License
; along with this program; if not, write to the Free Software
; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

; Written by: Panagiotis Manolios who can be reached as follows.

; Email: manolios@cc.gatech.edu

; Postal Mail:
; College of Computing
; CERCS Lab
; Georgia Institute of Technology
; 801 Atlantic Drive
; Atlanta, Georgia 30332-0280 U.S.A.

(in-package "ACL2")
(include-book "perm")
(include-book "total-order")

(defun <<= (x y)
  (lexorder x y))

(defun orderedp (x)
  (cond ((atom x) (null x))
	(t (or (null (cdr x))
	       (and (<<= (car x) (cadr x))
		    (orderedp (cdr x)))))))
