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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
|
/********************* */
/*! \file sygus-grammar.cpp
** \verbatim
** Top contributors (to current version):
** Abdalrhman Mohamed
** This file is part of the CVC4 project.
** Copyright (c) 2009-2020 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 Grammar to add syntax constraints to
** the Sygus solution for the identity function. Here is the same problem
** written in Sygus V2 format:
**
** (set-logic LIA)
**
** (synth-fun id1 ((x Int)) Int
** ((Start Int)) ((Start Int ((- x) (+ x Start)))))
**
** (synth-fun id2 ((x Int)) Int
** ((Start Int)) ((Start Int ((Variable Int) (- x) (+ x Start)))))
**
** (synth-fun id3 ((x Int)) Int
** ((Start Int)) ((Start Int (0 (- x) (+ x Start)))))
**
** (synth-fun id4 ((x Int)) Int
** ((Start Int)) ((Start Int ((- x) (+ x Start)))))
**
** (declare-var x Int)
**
** (constraint (= (id1 x) (id2 x) (id3 x) (id4 x) x))
**
** (check-synth)
**
** The printed output to this example should look like:
** (define-fun id1 ((x Int)) Int (+ x (+ x (- x))))
** (define-fun id2 ((x Int)) Int x)
** (define-fun id3 ((x Int)) Int (+ x 0))
** (define-fun id4 ((x Int)) Int (+ x (+ x (- x))))
**/
#include <cvc4/api/cvc4cpp.h>
#include <iostream>
using namespace CVC4::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();
// declare input variable for the function-to-synthesize
Term x = slv.mkVar(integer, "x");
// declare the grammar non-terminal
Term start = slv.mkVar(integer, "Start");
// define the rules
Term zero = slv.mkReal(0);
Term neg_x = slv.mkTerm(UMINUS, x);
Term plus = slv.mkTerm(PLUS, x, start);
// create the grammar object
Grammar g1 = slv.mkSygusGrammar({x}, {start});
// bind each non-terminal to its rules
g1.addRules(start, {neg_x, plus});
// copy the first grammar with all of its non-termainals and their rules
Grammar g2 = g1;
Grammar g3 = g1;
// add parameters as rules for the start symbol. Similar to "(Variable Int)"
g2.addAnyVariable(start);
// declare the functions-to-synthesize
Term id1 = slv.synthFun("id1", {x}, integer, g1);
Term id2 = slv.synthFun("id2", {x}, integer, g2);
g3.addRule(start, zero);
Term id3 = slv.synthFun("id3", {x}, integer, g3);
// g1 is reusable as long as it remains unmodified after first use
Term id4 = slv.synthFun("id4", {x}, integer, g1);
// declare universal variables.
Term varX = slv.mkSygusVar(integer, "x");
Term id1_x = slv.mkTerm(APPLY_UF, id1, varX);
Term id2_x = slv.mkTerm(APPLY_UF, id2, varX);
Term id3_x = slv.mkTerm(APPLY_UF, id3, varX);
Term id4_x = slv.mkTerm(APPLY_UF, id4, varX);
// add semantic constraints
// (constraint (= (id1 x) (id2 x) (id3 x) (id4 x) x))
slv.addSygusConstraint(slv.mkTerm(EQUAL, {id1_x, id2_x, id3_x, id4_x, varX}));
// print solutions if available
if (slv.checkSynth().isUnsat())
{
// Output should be equivalent to:
// (define-fun id1 ((x Int)) Int (+ x (+ x (- x))))
// (define-fun id2 ((x Int)) Int x)
// (define-fun id3 ((x Int)) Int (+ x 0))
// (define-fun id4 ((x Int)) Int (+ x (+ x (- x))))
slv.printSynthSolution(std::cout);
}
return 0;
}
|
