/usr/share/acl2-8.0dfsg/books/bdd/bool-ops.lisp is in acl2-books-source 8.0dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 | ; ACL2 books using the bdd hints
; Copyright (C) 1997 Computational Logic, Inc.
; License: A 3-clause BSD license. See the LICENSE file distributed with ACL2.
; Written by: Matt Kaufmann
; email: Matt_Kaufmann@aus.edsr.eds.com
; Computational Logic, Inc.
; 1717 West Sixth Street, Suite 290
; Austin, TX 78703-4776 U.S.A.
(in-package "ACL2")
(defun b-and (x y)
(declare (xargs :mode :logic
:verify-guards t))
(if x
(if y t nil)
nil))
(defun b-or (x y)
(declare (xargs :mode :logic
:verify-guards t))
(if x
t
(if y t nil)))
(defun b-xor (a b)
(declare (xargs :mode :logic
:verify-guards t))
(if a
(if b nil t)
(if b t nil)))
(defthm b-and-comm
(equal (b-and x y)
(b-and y x)))
(defthm b-or-comm
(equal (b-or x y)
(b-or y x)))
(defthm b-xor-comm
(equal (b-xor x y)
(b-xor y x)))
; The rest are theorems that one might prove, but we don't.
#|
(defthm b-xor-x-x
(equal (b-xor x x) nil))
(defthm b-and-x-x
(equal (b-and x x)
(if x t nil)))
(defthm b-or-x-x
(equal (b-or x x)
(if x t nil)))
(defthm b-xor-t-x
(equal (b-xor t x)
(if x nil t)))
(defthm b-xor-nil-x
(equal (b-xor nil x)
(if x t nil)))
(defthm b-and-t-x
(equal (b-and t x)
(if x t nil)))
(defthm b-and-nil-x
(equal (b-and nil x) nil))
(defthm b-or-t-x
(equal (b-or t x) t))
(defthm b-or-nil-x
(equal (b-or nil x)
(if x t nil)))
|#
|