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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
/********************* */
/*! \file cad_solver.cpp
** \verbatim
** Top contributors (to current version):
** Gereon Kremer
** 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 new non-linear solver
**/
#include "theory/arith/nl/cad_solver.h"
#ifdef CVC4_POLY_IMP
#include <poly/polyxx.h>
#endif
#include "theory/arith/inference_id.h"
#include "theory/arith/nl/cad/cdcac.h"
#include "theory/arith/nl/poly_conversion.h"
#include "util/poly_util.h"
namespace CVC4 {
namespace theory {
namespace arith {
namespace nl {
CadSolver::CadSolver(InferenceManager& im, NlModel& model)
: d_foundSatisfiability(false), d_im(im), d_model(model)
{
d_ranVariable =
NodeManager::currentNM()->mkSkolem("__z",
NodeManager::currentNM()->realType(),
"",
NodeManager::SKOLEM_EXACT_NAME);
}
CadSolver::~CadSolver() {}
void CadSolver::initLastCall(const std::vector<Node>& assertions)
{
#ifdef CVC4_POLY_IMP
if (Trace.isOn("nl-cad"))
{
Trace("nl-cad") << "CadSolver::initLastCall" << std::endl;
Trace("nl-cad") << "* Assertions: " << std::endl;
for (const Node& a : assertions)
{
Trace("nl-cad") << " " << a << std::endl;
}
}
// store or process assertions
d_CAC.reset();
for (const Node& a : assertions)
{
d_CAC.getConstraints().addConstraint(a);
}
d_CAC.computeVariableOrdering();
#else
Warning() << "Tried to use CadSolver but libpoly is not available. Compile "
"with --poly."
<< std::endl;
#endif
}
void CadSolver::checkFull()
{
#ifdef CVC4_POLY_IMP
auto covering = d_CAC.getUnsatCover();
if (covering.empty())
{
d_foundSatisfiability = true;
Trace("nl-cad") << "SAT: " << d_CAC.getModel() << std::endl;
}
else
{
d_foundSatisfiability = false;
auto mis = collectConstraints(covering);
Trace("nl-cad") << "Collected MIS: " << mis << std::endl;
Assert(!mis.empty()) << "Infeasible subset can not be empty";
Trace("nl-cad") << "UNSAT with MIS: " << mis << std::endl;
d_im.addConflict(NodeManager::currentNM()->mkAnd(mis),
InferenceId::NL_CAD_CONFLICT);
}
#else
Warning() << "Tried to use CadSolver but libpoly is not available. Compile "
"with --poly."
<< std::endl;
#endif
}
void CadSolver::checkPartial()
{
#ifdef CVC4_POLY_IMP
auto covering = d_CAC.getUnsatCover(0, true);
if (covering.empty())
{
d_foundSatisfiability = true;
Trace("nl-cad") << "SAT: " << d_CAC.getModel() << std::endl;
}
else
{
auto* nm = NodeManager::currentNM();
Node first_var =
d_CAC.getConstraints().varMapper()(d_CAC.getVariableOrdering()[0]);
for (const auto& interval : covering)
{
Node premise;
Assert(!interval.d_origins.empty());
if (interval.d_origins.size() == 1)
{
premise = interval.d_origins[0];
}
else
{
premise = nm->mkNode(Kind::AND, interval.d_origins);
}
Node conclusion =
excluding_interval_to_lemma(first_var, interval.d_interval, false);
if (!conclusion.isNull())
{
Node lemma = nm->mkNode(Kind::IMPLIES, premise, conclusion);
Trace("nl-cad") << "Excluding " << first_var << " -> "
<< interval.d_interval << " using " << lemma
<< std::endl;
d_im.addPendingArithLemma(lemma, InferenceId::NL_CAD_EXCLUDED_INTERVAL);
}
}
}
#else
Warning() << "Tried to use CadSolver but libpoly is not available. Compile "
"with --poly."
<< std::endl;
#endif
}
bool CadSolver::constructModelIfAvailable(std::vector<Node>& assertions)
{
#ifdef CVC4_POLY_IMP
if (!d_foundSatisfiability)
{
return false;
}
assertions.clear();
for (const auto& v : d_CAC.getVariableOrdering())
{
Node variable = d_CAC.getConstraints().varMapper()(v);
Node value = value_to_node(d_CAC.getModel().get(v), d_ranVariable);
if (value.isConst())
{
d_model.addCheckModelSubstitution(variable, value);
}
else
{
d_model.addCheckModelWitness(variable, value);
}
Trace("nl-cad") << "-> " << v << " = " << value << std::endl;
}
return true;
#else
Warning() << "Tried to use CadSolver but libpoly is not available. Compile "
"with --poly."
<< std::endl;
return false;
#endif
}
} // namespace nl
} // namespace arith
} // namespace theory
} // namespace CVC4
|
