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/********************* */
/*! \file instantiation_engine.cpp
** \verbatim
** Original author: ajreynol
** Major contributors: none
** Minor contributors (to current version): none
** This file is part of the CVC4 prototype.
** Copyright (c) 2009, 2010, 2011 The Analysis of Computer Systems Group (ACSys)
** Courant Institute of Mathematical Sciences
** New York University
** See the file COPYING in the top-level source directory for licensing
** information.\endverbatim
**
** \brief Implementation of instantiation engine class
**/
#include "theory/quantifiers/instantiation_engine.h"
#include "theory/theory_engine.h"
#include "theory/uf/theory_uf_instantiator.h"
using namespace std;
using namespace CVC4;
using namespace CVC4::kind;
using namespace CVC4::context;
using namespace CVC4::theory;
using namespace CVC4::theory::quantifiers;
//#define IE_PRINT_PROCESS_TIMES
InstantiationEngine::InstantiationEngine( TheoryQuantifiers* th ) :
d_th( th ){
}
QuantifiersEngine* InstantiationEngine::getQuantifiersEngine(){
return d_th->getQuantifiersEngine();
}
bool InstantiationEngine::hasAddedCbqiLemma( Node f ) {
return d_ce_lit.find( f ) != d_ce_lit.end();
}
void InstantiationEngine::addCbqiLemma( Node f ){
Assert( doCbqi( f ) && !hasAddedCbqiLemma( f ) );
//code for counterexample-based quantifier instantiation
Debug("cbqi") << "Do cbqi for " << f << std::endl;
//make the counterexample body
//Node ceBody = f[1].substitute( getQuantifiersEngine()->d_vars[f].begin(), getQuantifiersEngine()->d_vars[f].end(),
// getQuantifiersEngine()->d_inst_constants[f].begin(),
// getQuantifiersEngine()->d_inst_constants[f].end() );
//get the counterexample literal
Node ceBody = getQuantifiersEngine()->getCounterexampleBody( f );
Node ceLit = d_th->getValuation().ensureLiteral( ceBody.notNode() );
d_ce_lit[ f ] = ceLit;
getQuantifiersEngine()->setInstantiationConstantAttr( ceLit, f );
// set attributes, mark all literals in the body of n as dependent on cel
//registerLiterals( ceLit, f );
//require any decision on cel to be phase=true
d_th->getOutputChannel().requirePhase( ceLit, true );
Debug("cbqi-debug") << "Require phase " << ceLit << " = true." << std::endl;
//add counterexample lemma
NodeBuilder<> nb(kind::OR);
nb << f << ceLit;
Node lem = nb;
Debug("cbqi-debug") << "Counterexample lemma : " << lem << std::endl;
d_th->getOutputChannel().lemma( lem );
}
bool InstantiationEngine::doInstantiationRound( Theory::Effort effort ){
//if counterexample-based quantifier instantiation is active
if( Options::current()->cbqi ){
//check if any cbqi lemma has not been added yet
bool addedLemma = false;
for( int i=0; i<(int)getQuantifiersEngine()->getNumAssertedQuantifiers(); i++ ){
Node f = getQuantifiersEngine()->getAssertedQuantifier( i );
if( doCbqi( f ) && !hasAddedCbqiLemma( f ) ){
//add cbqi lemma
addCbqiLemma( f );
addedLemma = true;
}
}
if( addedLemma ){
return true;
}
}
//if not, proceed to instantiation round
Debug("inst-engine") << "IE: Instantiation Round." << std::endl;
Debug("inst-engine-ctrl") << "IE: Instantiation Round." << std::endl;
//reset instantiators
Debug("inst-engine-ctrl") << "Reset IE" << std::endl;
for( int i=0; i<theory::THEORY_LAST; i++ ){
if( getQuantifiersEngine()->getInstantiator( i ) ){
getQuantifiersEngine()->getInstantiator( i )->resetInstantiationRound( effort );
}
}
getQuantifiersEngine()->getTermDatabase()->reset( effort );
//iterate over an internal effort level e
int e = 0;
int eLimit = effort==Theory::EFFORT_LAST_CALL ? 10 : 2;
d_inst_round_status = InstStrategy::STATUS_UNFINISHED;
//while unfinished, try effort level=0,1,2....
while( d_inst_round_status==InstStrategy::STATUS_UNFINISHED && e<=eLimit ){
Debug("inst-engine") << "IE: Prepare instantiation (" << e << ")." << std::endl;
d_inst_round_status = InstStrategy::STATUS_SAT;
//instantiate each quantifier
for( int q=0; q<getQuantifiersEngine()->getNumAssertedQuantifiers(); q++ ){
Node f = getQuantifiersEngine()->getAssertedQuantifier( q );
Debug("inst-engine-debug") << "IE: Instantiate " << f << "..." << std::endl;
//if this quantifier is active
if( getQuantifiersEngine()->getActive( f ) ){
//int e_use = getQuantifiersEngine()->getRelevance( f )==-1 ? e - 1 : e;
int e_use = e;
if( e_use>=0 ){
//use each theory instantiator to instantiate f
for( int i=0; i<theory::THEORY_LAST; i++ ){
if( getQuantifiersEngine()->getInstantiator( i ) ){
Debug("inst-engine-debug") << "Do " << getQuantifiersEngine()->getInstantiator( i )->identify() << " " << e_use << std::endl;
int limitInst = 0;
int quantStatus = getQuantifiersEngine()->getInstantiator( i )->doInstantiation( f, effort, e_use, limitInst );
Debug("inst-engine-debug") << " -> status is " << quantStatus << std::endl;
InstStrategy::updateStatus( d_inst_round_status, quantStatus );
}
}
}
}
}
//do not consider another level if already added lemma at this level
if( getQuantifiersEngine()->hasAddedLemma() ){
d_inst_round_status = InstStrategy::STATUS_UNKNOWN;
}
e++;
}
Debug("inst-engine") << "All instantiators finished, # added lemmas = ";
Debug("inst-engine") << (int)getQuantifiersEngine()->d_lemmas_waiting.size() << std::endl;
//Notice() << "All instantiators finished, # added lemmas = " << (int)d_lemmas_waiting.size() << std::endl;
if( !getQuantifiersEngine()->hasAddedLemma() ){
Debug("inst-engine-stuck") << "No instantiations produced at this state: " << std::endl;
for( int i=0; i<theory::THEORY_LAST; i++ ){
if( getQuantifiersEngine()->getInstantiator( i ) ){
getQuantifiersEngine()->getInstantiator( i )->debugPrint("inst-engine-stuck");
Debug("inst-engine-stuck") << std::endl;
}
}
Debug("inst-engine-ctrl") << "---Fail." << std::endl;
return false;
}else{
Debug("inst-engine-ctrl") << "---Done. " << (int)getQuantifiersEngine()->d_lemmas_waiting.size() << std::endl;
#ifdef IE_PRINT_PROCESS_TIMES
Notice() << "lemmas = " << (int)getQuantifiersEngine()->d_lemmas_waiting.size() << std::endl;
#endif
//flush lemmas to output channel
getQuantifiersEngine()->flushLemmas( &d_th->getOutputChannel() );
return true;
}
}
int ierCounter = 0;
void InstantiationEngine::check( Theory::Effort e ){
if( e==Theory::EFFORT_FULL ){
ierCounter++;
}
//determine if we should perform check, based on instWhenMode
bool performCheck = false;
if( Options::current()->instWhenMode==Options::INST_WHEN_FULL ){
performCheck = ( e >= Theory::EFFORT_FULL );
}else if( Options::current()->instWhenMode==Options::INST_WHEN_FULL_LAST_CALL ){
performCheck = ( ( e==Theory::EFFORT_FULL && ierCounter%2==0 ) || e==Theory::EFFORT_LAST_CALL );
}else if( Options::current()->instWhenMode==Options::INST_WHEN_LAST_CALL ){
performCheck = ( e >= Theory::EFFORT_LAST_CALL );
}else{
performCheck = true;
}
if( performCheck ){
Debug("inst-engine") << "IE: Check " << e << " " << ierCounter << std::endl;
#ifdef IE_PRINT_PROCESS_TIMES
double clSet = double(clock())/double(CLOCKS_PER_SEC);
Notice() << "Run instantiation round " << e << " " << ierCounter << std::endl;
#endif
bool quantActive = false;
//for each quantifier currently asserted,
// such that the counterexample literal is not in positive in d_counterexample_asserts
// for( BoolMap::iterator i = d_forall_asserts.begin(); i != d_forall_asserts.end(); i++ ) {
// if( (*i).second ) {
for( int i=0; i<(int)getQuantifiersEngine()->getNumAssertedQuantifiers(); i++ ){
Node n = getQuantifiersEngine()->getAssertedQuantifier( i );
if( Options::current()->cbqi && hasAddedCbqiLemma( n ) ){
Node cel = d_ce_lit[ n ];
bool active, value;
bool ceValue = false;
if( d_th->getValuation().hasSatValue( cel, value ) ){
active = value;
ceValue = true;
}else{
active = true;
}
getQuantifiersEngine()->setActive( n, active );
if( active ){
Debug("quantifiers") << " Active : " << n;
quantActive = true;
}else{
Debug("quantifiers") << " NOT active : " << n;
if( d_th->getValuation().isDecision( cel ) ){
Debug("quant-req-phase") << "Bad decision : " << cel << std::endl;
}
//note that the counterexample literal must not be a decision
Assert( !d_th->getValuation().isDecision( cel ) );
}
if( d_th->getValuation().hasSatValue( n, value ) ){
Debug("quantifiers") << ", value = " << value;
}
if( ceValue ){
Debug("quantifiers") << ", ce is asserted";
}
Debug("quantifiers") << std::endl;
}else{
getQuantifiersEngine()->setActive( n, true );
quantActive = true;
Debug("quantifiers") << " Active : " << n << ", no ce assigned." << std::endl;
}
Debug("quantifiers-relevance") << "Quantifier : " << n << std::endl;
Debug("quantifiers-relevance") << " Relevance : " << getQuantifiersEngine()->getRelevance( n ) << std::endl;
Debug("quantifiers") << " Relevance : " << getQuantifiersEngine()->getRelevance( n ) << std::endl;
}
//}
if( quantActive ){
bool addedLemmas = doInstantiationRound( e );
//Debug("quantifiers-dec") << "Do instantiation, level = " << d_th->getValuation().getDecisionLevel() << std::endl;
//for( int i=1; i<=(int)d_valuation.getDecisionLevel(); i++ ){
// Debug("quantifiers-dec") << " " << d_valuation.getDecision( i ) << std::endl;
//}
if( e==Theory::EFFORT_LAST_CALL ){
if( !addedLemmas ){
if( d_inst_round_status==InstStrategy::STATUS_SAT ){
Debug("inst-engine") << "No instantiation given, returning SAT..." << std::endl;
debugSat( SAT_INST_STRATEGY );
}else{
Debug("inst-engine") << "No instantiation given, returning unknown..." << std::endl;
d_th->getOutputChannel().setIncomplete();
}
}
}
}else{
if( e==Theory::EFFORT_LAST_CALL ){
if( Options::current()->cbqi ){
debugSat( SAT_CBQI );
}
}
}
#ifdef IE_PRINT_PROCESS_TIMES
double clSet2 = double(clock())/double(CLOCKS_PER_SEC);
Notice() << "Done Run instantiation round " << (clSet2-clSet) << std::endl;
#endif
}
}
void InstantiationEngine::registerQuantifier( Node f ){
//Notice() << "do cbqi " << f << " ? " << std::endl;
Node ceBody = getQuantifiersEngine()->getCounterexampleBody( f );
if( !doCbqi( f ) ){
getQuantifiersEngine()->addTermToDatabase( ceBody, true );
//need to tell which instantiators will be responsible
//by default, just chose the UF instantiator
getQuantifiersEngine()->getInstantiator( theory::THEORY_UF )->setHasConstraintsFrom( f );
}
//take into account user patterns
if( f.getNumChildren()==3 ){
Node subsPat = getQuantifiersEngine()->getSubstitutedNode( f[2], f );
//add patterns
for( int i=0; i<(int)subsPat.getNumChildren(); i++ ){
//Notice() << "Add pattern " << subsPat[i] << " for " << f << std::endl;
((uf::InstantiatorTheoryUf*)getQuantifiersEngine()->getInstantiator( theory::THEORY_UF ))->addUserPattern( f, subsPat[i] );
}
}
}
void InstantiationEngine::assertNode( Node f ){
////if we are doing cbqi and have not added the lemma yet, do so
//if( doCbqi( f ) && !hasAddedCbqiLemma( f ) ){
// addCbqiLemma( f );
//}
}
bool InstantiationEngine::hasApplyUf( Node f ){
if( f.getKind()==APPLY_UF ){
return true;
}else{
for( int i=0; i<(int)f.getNumChildren(); i++ ){
if( hasApplyUf( f[i] ) ){
return true;
}
}
return false;
}
}
bool InstantiationEngine::hasNonArithmeticVariable( Node f ){
for( int i=0; i<(int)f[0].getNumChildren(); i++ ){
TypeNode tn = f[0][i].getType();
if( !tn.isInteger() && !tn.isReal() ){
return true;
}
}
return false;
}
bool InstantiationEngine::doCbqi( Node f ){
if( Options::current()->cbqiSetByUser ){
return Options::current()->cbqi;
}else if( Options::current()->cbqi ){
//if quantifier has a non-arithmetic variable, then do not use cbqi
//if quantifier has an APPLY_UF term, then do not use cbqi
return !hasNonArithmeticVariable( f ) && !hasApplyUf( f[1] );
}else{
return false;
}
}
//void InstantiationEngine::registerLiterals( Node n, Node f ){
// if( n.getAttribute(InstConstantAttribute())==f ){
// for( int i=0; i<(int)n.getNumChildren(); i++ ){
// registerLiterals( n[i], f );
// }
// if( !d_ce_lit[ f ].isNull() ){
// if( getQuantifiersEngine()->d_te->getPropEngine()->isSatLiteral( n ) && n.getKind()!=NOT ){
// if( n!=d_ce_lit[ f ] && n.notNode()!=d_ce_lit[ f ] ){
// Debug("quant-dep-dec") << "Make " << n << " dependent on ";
// Debug("quant-dep-dec") << d_ce_lit[ f ] << std::endl;
// d_th->getOutputChannel().dependentDecision( d_ce_lit[ f ], n );
// }
// }
// }
// }
//}
void InstantiationEngine::debugSat( int reason ){
if( reason==SAT_CBQI ){
//Debug("quantifiers-sat") << "Decisions:" << std::endl;
//for( int i=1; i<=(int)d_th->getValuation().getDecisionLevel(); i++ ){
// Debug("quantifiers-sat") << " " << i << ": " << d_th->getValuation().getDecision( i ) << std::endl;
//}
//for( BoolMap::iterator i = d_forall_asserts.begin(); i != d_forall_asserts.end(); i++ ) {
// if( (*i).second ) {
for( int i=0; i<(int)getQuantifiersEngine()->getNumAssertedQuantifiers(); i++ ){
Node f = getQuantifiersEngine()->getAssertedQuantifier( i );
Node cel = d_ce_lit[ f ];
Assert( !cel.isNull() );
bool value;
if( d_th->getValuation().hasSatValue( cel, value ) ){
if( !value ){
AlwaysAssert(! d_th->getValuation().isDecision( cel ),
"bad decision on counterexample literal");
}
}
}
//}
Debug("quantifiers-sat") << "return SAT: Cbqi, no quantifier is active. " << std::endl;
//static bool setTrust = false;
//if( !setTrust ){
// setTrust = true;
// Notice() << "trust-";
//}
}else if( reason==SAT_INST_STRATEGY ){
Debug("quantifiers-sat") << "return SAT: No strategy chose to add an instantiation." << std::endl;
//Notice() << "sat ";
//Unimplemented();
}
}
void InstantiationEngine::propagate( Theory::Effort level ){
//propagate as decision all counterexample literals that are not asserted
for( std::map< Node, Node >::iterator it = d_ce_lit.begin(); it != d_ce_lit.end(); ++it ){
bool value;
if( !d_th->getValuation().hasSatValue( it->second, value ) ){
//if not already set, propagate as decision
d_th->getOutputChannel().propagateAsDecision( it->second );
Debug("cbqi-prop-as-dec") << "CBQI: propagate as decision " << it->second << std::endl;
}
}
}
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