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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
|
; Copyright (C) 2009 Centaur Technology
;
; Contact:
; Centaur Technology Formal Verification Group
; 7600-C N. Capital of Texas Highway, Suite 300, Austin, TX 78731, USA.
; http://www.centtech.com/
;
; License: (An MIT/X11-style license)
;
; Permission is hereby granted, free of charge, to any person obtaining a
; copy of this software and associated documentation files (the "Software"),
; to deal in the Software without restriction, including without limitation
; the rights to use, copy, modify, merge, publish, distribute, sublicense,
; and/or sell copies of the Software, and to permit persons to whom the
; Software is furnished to do so, subject to the following conditions:
;
; The above copyright notice and this permission notice shall be included in
; all copies or substantial portions of the Software.
;
; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
; DEALINGS IN THE SOFTWARE.
;
; Original author: Sol Swords <sswords@centtech.com>
;; This is a computed hint that causes a :by hint to be applied to a subgoal
;; when the first hyp in the clause is (use-by-hint thmname).
;; This can enable clause processors to make use of user-provided,
;; pre-proven ACL2 theorems. For example, assume a clause processor does
;; something with user-provided theorems and the following theorem is provided
;; to it by the user:
;; (defthm foo-thm (implies (bar x) (equal (foo x) 'baz)))
;; In general, to use the fact provided by this theorem, the clause processor
;; must prove this theorem again. A quick/easy way to do this is to produce
;; the clause
;; `((not (use-by-hint 'foo-thm))
;; (implies (bar x) (equal (foo x) 'baz)))
;; If the user (or, say, a computed hint that calls the clause processor)
;; ensures that a (use-by-computed-hint clause) fires when ACL2 attempts to
;; prove this clause, it should then be discharged immediately.
;; See also clause-processors/multi-env-trick for additional help with making
;; clause processors that use user-provided lemmas.
(in-package "ACL2")
;; (include-book "join-thms")
(include-book "remove-hyp")
(include-book "std/util/bstar" :dir :system)
;; USE-BY-HINT is t. Therefore it can be added as a hyp to any subgoal without
;; affecting its truth value. It serves to signal use-by-computed-hint to give
;; a particular :by hint.
(defun use-by-hint (x)
(declare (ignore x))
t)
(in-theory (disable use-by-hint
(use-by-hint)
(:type-prescription use-by-hint)))
;; The computed hint. Checks to see if the first literal in the clause is a
;; hyp of the form (use-by-hint 'rulename). If so, first remove that literal
;; using remove-first-hyp-cp, then give a :by hint with that rule.
(defun use-by-computed-hint (clause)
(declare (xargs :mode :program))
(case-match clause
((('not ('use-by-hint ('quote rule . &) . &) . &) . &)
`(:computed-hint-replacement
('(:by ,rule :do-not '(preprocess simplify)))
:clause-processor remove-first-hyp-cp))
(& nil)))
(defun use-these-hints (x)
(declare (ignore x))
t)
(in-theory (disable use-these-hints (use-these-hints)
(:type-prescription use-these-hints)))
(defun use-these-hints-hint (clause)
(case-match clause
((('not ('use-these-hints ('quote the-hints . &) . &) . &) . &)
`(:computed-hint-replacement
,the-hints
:clause-processor remove-first-hyp-cp))
(& nil)))
;; Note: the use-termhint utility used to be here but has been moved to std/util/termhints.lisp.
|
