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
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/********************* */
/*! \file expr_miner.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Andres Noetzli
** This file is part of the CVC4 project.
** Copyright (c) 2009-2019 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 Implementation of expr_miner
**/
#include "theory/quantifiers/expr_miner.h"
#include "options/quantifiers_options.h"
#include "smt/smt_engine.h"
#include "smt/smt_engine_scope.h"
#include "theory/quantifiers/term_util.h"
using namespace std;
using namespace CVC4::kind;
namespace CVC4 {
namespace theory {
namespace quantifiers {
void ExprMiner::initialize(const std::vector<Node>& vars, SygusSampler* ss)
{
d_sampler = ss;
d_vars.insert(d_vars.end(), vars.begin(), vars.end());
}
Node ExprMiner::convertToSkolem(Node n)
{
std::vector<Node> fvs;
TermUtil::computeVarContains(n, fvs);
if (fvs.empty())
{
return n;
}
std::vector<Node> sfvs;
std::vector<Node> sks;
// map to skolems
NodeManager* nm = NodeManager::currentNM();
for (unsigned i = 0, size = fvs.size(); i < size; i++)
{
Node v = fvs[i];
// only look at the sampler variables
if (std::find(d_vars.begin(), d_vars.end(), v) != d_vars.end())
{
sfvs.push_back(v);
std::map<Node, Node>::iterator itf = d_fv_to_skolem.find(v);
if (itf == d_fv_to_skolem.end())
{
Node sk = nm->mkSkolem("rrck", v.getType());
d_fv_to_skolem[v] = sk;
sks.push_back(sk);
}
else
{
sks.push_back(itf->second);
}
}
}
return n.substitute(sfvs.begin(), sfvs.end(), sks.begin(), sks.end());
}
void ExprMiner::initializeChecker(std::unique_ptr<SmtEngine>& checker,
ExprManager& em,
ExprManagerMapCollection& varMap,
Node query,
bool& needExport)
{
// Convert bound variables to skolems. This ensures the satisfiability
// check is ground.
Node squery = convertToSkolem(query);
NodeManager* nm = NodeManager::currentNM();
if (options::sygusExprMinerCheckUseExport())
{
// To support a separate timeout for the subsolver, we need to create
// a separate ExprManager with its own options. This requires that
// the expressions sent to the subsolver can be exported from on
// ExprManager to another. If the export fails, we throw an
// OptionException.
try
{
checker.reset(new SmtEngine(&em));
checker->setIsInternalSubsolver();
checker->setTimeLimit(options::sygusExprMinerCheckTimeout(), true);
checker->setLogic(smt::currentSmtEngine()->getLogicInfo());
checker->setOption("sygus-rr-synth-input", false);
checker->setOption("sygus-abduct", false);
checker->setOption("input-language", "smt2");
Expr equery = squery.toExpr().exportTo(&em, varMap);
checker->assertFormula(equery);
}
catch (const CVC4::ExportUnsupportedException& e)
{
std::stringstream msg;
msg << "Unable to export " << squery
<< " but exporting expressions is "
"required for an expression "
"miner check.";
throw OptionException(msg.str());
}
needExport = true;
}
else
{
needExport = false;
checker.reset(new SmtEngine(nm->toExprManager()));
checker->assertFormula(squery.toExpr());
}
}
Result ExprMiner::doCheck(Node query)
{
Node queryr = Rewriter::rewrite(query);
if (queryr.isConst())
{
if (!queryr.getConst<bool>())
{
return Result(Result::UNSAT);
}
else
{
return Result(Result::SAT);
}
}
NodeManager* nm = NodeManager::currentNM();
bool needExport = false;
ExprManager em(nm->getOptions());
std::unique_ptr<SmtEngine> smte;
ExprManagerMapCollection varMap;
initializeChecker(smte, em, varMap, queryr, needExport);
return smte->checkSat();
}
} // namespace quantifiers
} // namespace theory
} // namespace CVC4
|
