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/********************* */
/*! \file inst_strategy_enumerative.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Morgan Deters
** 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 Implementation of an enumerative instantiation strategy.
**/
#include "theory/quantifiers/inst_strategy_enumerative.h"
#include "options/quantifiers_options.h"
#include "theory/quantifiers/instantiate.h"
#include "theory/quantifiers/relevant_domain.h"
#include "theory/quantifiers/term_database.h"
#include "theory/quantifiers/term_tuple_enumerator.h"
#include "theory/quantifiers/term_util.h"
#include "theory/quantifiers_engine.h"
namespace CVC4 {
using namespace kind;
using namespace context;
namespace theory {
namespace quantifiers {
using namespace inst;
InstStrategyEnum::InstStrategyEnum(QuantifiersEngine* qe,
QuantifiersState& qs,
QuantifiersInferenceManager& qim,
QuantifiersRegistry& qr,
RelevantDomain* rd)
: QuantifiersModule(qs, qim, qr, qe), d_rd(rd), d_fullSaturateLimit(-1)
{
}
void InstStrategyEnum::presolve()
{
d_fullSaturateLimit = options::fullSaturateLimit();
}
bool InstStrategyEnum::needsCheck(Theory::Effort e)
{
if (d_fullSaturateLimit == 0)
{
return false;
}
if (options::fullSaturateInterleave())
{
// if interleaved, we run at the same time as E-matching
if (d_qstate.getInstWhenNeedsCheck(e))
{
return true;
}
}
if (options::fullSaturateQuant())
{
if (e >= Theory::EFFORT_LAST_CALL)
{
return true;
}
}
return false;
}
void InstStrategyEnum::reset_round(Theory::Effort e) {}
void InstStrategyEnum::check(Theory::Effort e, QEffort quant_e)
{
bool doCheck = false;
bool fullEffort = false;
if (d_fullSaturateLimit != 0)
{
if (options::fullSaturateInterleave())
{
// we only add when interleaved with other strategies
doCheck = quant_e == QEFFORT_STANDARD && d_qim.hasPendingLemma();
}
if (options::fullSaturateQuant() && !doCheck)
{
if (!d_qstate.getValuation().needCheck())
{
doCheck = quant_e == QEFFORT_LAST_CALL;
fullEffort = true;
}
}
}
if (!doCheck)
{
return;
}
Assert(!d_qstate.isInConflict());
double clSet = 0;
if (Trace.isOn("fs-engine"))
{
clSet = double(clock()) / double(CLOCKS_PER_SEC);
Trace("fs-engine") << "---Full Saturation Round, effort = " << e << "---"
<< std::endl;
}
unsigned rstart = options::fullSaturateQuantRd() ? 0 : 1;
unsigned rend = fullEffort ? 1 : rstart;
unsigned addedLemmas = 0;
// First try in relevant domain of all quantified formulas, if no
// instantiations exist, try arbitrary ground terms.
// Notice that this stratification of effort levels makes it so that some
// quantified formulas may not be instantiated (if they have no instances
// at effort level r=0 but another quantified formula does). We prefer
// this stratification since effort level r=1 may be highly expensive in the
// case where we have a quantified formula with many entailed instances.
FirstOrderModel* fm = d_quantEngine->getModel();
unsigned nquant = fm->getNumAssertedQuantifiers();
std::map<Node, bool> alreadyProc;
for (unsigned r = rstart; r <= rend; r++)
{
if (d_rd || r > 0)
{
if (r == 0)
{
Trace("inst-alg") << "-> Relevant domain instantiate..." << std::endl;
Trace("inst-alg-debug") << "Compute relevant domain..." << std::endl;
d_rd->compute();
Trace("inst-alg-debug") << "...finished" << std::endl;
}
else
{
Trace("inst-alg") << "-> Ground term instantiate..." << std::endl;
}
for (unsigned i = 0; i < nquant; i++)
{
Node q = fm->getAssertedQuantifier(i, true);
bool doProcess = d_qreg.hasOwnership(q, this)
&& fm->isQuantifierActive(q)
&& alreadyProc.find(q) == alreadyProc.end();
if (doProcess)
{
if (process(q, fullEffort, r == 0))
{
// don't need to mark this if we are not stratifying
if (!options::fullSaturateStratify())
{
alreadyProc[q] = true;
}
// added lemma
addedLemmas++;
}
if (d_qstate.isInConflict())
{
break;
}
}
}
if (d_qstate.isInConflict()
|| (addedLemmas > 0 && options::fullSaturateStratify()))
{
// we break if we are in conflict, or if we added any lemma at this
// effort level and we stratify effort levels.
break;
}
}
}
if (Trace.isOn("fs-engine"))
{
Trace("fs-engine") << "Added lemmas = " << addedLemmas << std::endl;
double clSet2 = double(clock()) / double(CLOCKS_PER_SEC);
Trace("fs-engine") << "Finished full saturation engine, time = "
<< (clSet2 - clSet) << std::endl;
}
if (d_fullSaturateLimit > 0)
{
d_fullSaturateLimit--;
}
}
bool InstStrategyEnum::process(Node quantifier, bool fullEffort, bool isRd)
{
// ignore if constant true (rare case of non-standard quantifier whose body
// is rewritten to true)
if (quantifier[1].isConst() && quantifier[1].getConst<bool>())
{
return false;
}
TermTupleEnumeratorContext ttec;
ttec.d_quantEngine = d_quantEngine;
ttec.d_rd = d_rd;
ttec.d_fullEffort = fullEffort;
ttec.d_increaseSum = options::fullSaturateSum();
ttec.d_isRd = isRd;
std::unique_ptr<TermTupleEnumeratorInterface> enumerator(
mkTermTupleEnumerator(quantifier, &ttec));
std::vector<Node> terms;
std::vector<bool> failMask;
Instantiate* ie = d_qim.getInstantiate();
for (enumerator->init(); enumerator->hasNext();)
{
if (d_qstate.isInConflict())
{
// could be conflicting for an internal reason
return false;
}
enumerator->next(terms);
// try instantiation
failMask.clear();
/* if (ie->addInstantiation(quantifier, terms)) */
if (ie->addInstantiationExpFail(
quantifier, terms, failMask, InferenceId::QUANTIFIERS_INST_ENUM))
{
Trace("inst-alg-rd") << "Success!" << std::endl;
return true;
}
else
{
enumerator->failureReason(failMask);
}
}
return false;
// TODO : term enumerator instantiation?
}
} // namespace quantifiers
} // namespace theory
} // namespace CVC4
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