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
|
/********************* */
/*! \file sygus-inv.cpp
** \verbatim
** Top contributors (to current version):
** Abdalrhman Mohamed, Mudathir Mohamed
** This file is part of the CVC4 project.
** Copyright (c) 2009-2021 by the authors listed in the file AUTHORS
** in the top-level source directory and their institutional affiliations.
** All rights reserved. See the file COPYING in the top-level source
** directory for licensing information.\endverbatim
**
** \brief A simple demonstration of the Sygus API.
**
** A simple demonstration of how to use the Sygus API to synthesize a simple
** invariant. Here is the same problem written in Sygus V2 format:
**
** (set-logic LIA)
**
** (synth-inv inv-f ((x Int)))
**
** (define-fun pre-f ((x Int)) Bool
** (= x 0))
** (define-fun trans-f ((x Int) (xp Int)) Bool
** (ite (< x 10) (= xp (+ x 1)) (= xp x)))
** (define-fun post-f ((x Int)) Bool
** (<= x 10))
**
** (inv-constraint inv-f pre-f trans-f post-f)
**
** (check-synth)
**
** The printed output to this example should be equivalent to:
** (define-fun inv-f ((x Int)) Bool (not (>= x 11)))
**/
#include <cvc4/api/cvc4cpp.h>
#include <iostream>
using namespace CVC5::api;
int main()
{
Solver slv;
// required options
slv.setOption("lang", "sygus2");
slv.setOption("incremental", "false");
// set the logic
slv.setLogic("LIA");
Sort integer = slv.getIntegerSort();
Sort boolean = slv.getBooleanSort();
Term zero = slv.mkInteger(0);
Term one = slv.mkInteger(1);
Term ten = slv.mkInteger(10);
// declare input variables for functions
Term x = slv.mkVar(integer, "x");
Term xp = slv.mkVar(integer, "xp");
// (ite (< x 10) (= xp (+ x 1)) (= xp x))
Term ite = slv.mkTerm(ITE,
slv.mkTerm(LT, x, ten),
slv.mkTerm(EQUAL, xp, slv.mkTerm(PLUS, x, one)),
slv.mkTerm(EQUAL, xp, x));
// define the pre-conditions, transition relations, and post-conditions
Term pre_f = slv.defineFun("pre-f", {x}, boolean, slv.mkTerm(EQUAL, x, zero));
Term trans_f = slv.defineFun("trans-f", {x, xp}, boolean, ite);
Term post_f = slv.defineFun("post-f", {x}, boolean, slv.mkTerm(LEQ, x, ten));
// declare the invariant-to-synthesize
Term inv_f = slv.synthInv("inv-f", {x});
slv.addSygusInvConstraint(inv_f, pre_f, trans_f, post_f);
// print solutions if available
if (slv.checkSynth().isUnsat())
{
// Output should be equivalent to:
// (define-fun inv-f ((x Int)) Bool (not (>= x 11)))
slv.printSynthSolution(std::cout);
}
return 0;
}
|
