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/********************* */
/*! \file quant_equality_engine.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Tim King
** This file is part of the CVC4 project.
** Copyright (c) 2009-2016 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
**
** Congruence closure with free variables
**/
#include <vector>
#include "theory/quantifiers/quant_equality_engine.h"
#include "theory/rewriter.h"
#include "theory/quantifiers/term_database.h"
using namespace CVC4;
using namespace std;
using namespace CVC4::theory;
using namespace CVC4::theory::quantifiers;
using namespace CVC4::kind;
QuantEqualityEngine::QuantEqualityEngine( QuantifiersEngine * qe, context::Context* c ) :
QuantifiersModule( qe ),
d_notify( *this ),
d_uequalityEngine(d_notify, c, "theory::quantifiers::QuantEqualityEngine", true),
d_conflict(c, false),
d_quant_red(c),
d_quant_unproc(c){
d_uequalityEngine.addFunctionKind( kind::APPLY_UF );
d_intType = NodeManager::currentNM()->integerType();
}
void QuantEqualityEngine::conflict(TNode t1, TNode t2) {
//report conflict through quantifiers engine output channel
std::vector<TNode> assumptions;
d_uequalityEngine.explainEquality(t1, t2, true, assumptions, NULL);
Node conflict;
if( assumptions.size()==1 ){
conflict = assumptions[0];
}else{
conflict = NodeManager::currentNM()->mkNode( AND, assumptions );
}
d_conflict = true;
Trace("qee-conflict") << "Quantifier equality engine conflict : " << conflict << std::endl;
d_quantEngine->getOutputChannel().conflict( conflict );
}
void QuantEqualityEngine::eqNotifyNewClass(TNode t){
}
void QuantEqualityEngine::eqNotifyPreMerge(TNode t1, TNode t2){
}
void QuantEqualityEngine::eqNotifyPostMerge(TNode t1, TNode t2){
}
void QuantEqualityEngine::eqNotifyDisequal(TNode t1, TNode t2, TNode reason) {
}
/* whether this module needs to check this round */
bool QuantEqualityEngine::needsCheck( Theory::Effort e ) {
return e>=Theory::EFFORT_LAST_CALL;
}
/* reset at a round */
void QuantEqualityEngine::reset_round( Theory::Effort e ){
//TODO
}
/* Call during quantifier engine's check */
void QuantEqualityEngine::check( Theory::Effort e, unsigned quant_e ) {
//TODO
}
/* Called for new quantifiers */
void QuantEqualityEngine::registerQuantifier( Node q ) {
//TODO
}
/** called for everything that gets asserted */
void QuantEqualityEngine::assertNode( Node n ) {
Assert( n.getKind()==FORALL );
Trace("qee-debug") << "QEE assert : " << n << std::endl;
if( !d_conflict ){
Node lit = n[1].getKind()==NOT ? n[1][0] : n[1];
bool pol = n[1].getKind()!=NOT;
bool success = true;
Node t1;
Node t2;
if( lit.getKind()==APPLY_UF || lit.getKind()==EQUAL ){
lit = getTermDatabase()->getCanonicalTerm( lit );
Trace("qee-debug") << "Canonical : " << lit << ", pol = " << pol << std::endl;
if( lit.getKind()==APPLY_UF ){
t1 = getFunctionAppForPredicateApp( lit );
t2 = pol ? getTermDatabase()->d_one : getTermDatabase()->d_zero;
pol = true;
lit = NodeManager::currentNM()->mkNode( EQUAL, t1, t2 );
}else if( lit.getKind()==EQUAL ){
if( lit[0].getType().isBoolean() ){
if( lit[0].getKind()==NOT ){
t1 = lit[0][0];
pol = !pol;
}else{
t1 = lit[0];
}
if( lit[1].getKind()==NOT ){
t2 = lit[1][0];
pol = !pol;
}else{
t2 = lit[1];
}
if( t1.getKind()==APPLY_UF && t2.getKind()==APPLY_UF ){
t1 = getFunctionAppForPredicateApp( t1 );
t2 = getFunctionAppForPredicateApp( t2 );
lit = NodeManager::currentNM()->mkNode( EQUAL, t1, t2 );
}else{
success = false;
}
}else{
t1 = lit[0];
t2 = lit[1];
}
}
}else{
success = false;
}
if( success ){
bool alreadyHolds = false;
if( pol && areUnivEqualInternal( t1, t2 ) ){
alreadyHolds = true;
}else if( !pol && areUnivDisequalInternal( t1, t2 ) ){
alreadyHolds = true;
}
if( alreadyHolds ){
d_quant_red.push_back( n );
Trace("qee-debug") << "...add to redundant" << std::endl;
}else{
Trace("qee-debug") << "...assert" << std::endl;
Trace("qee-assert") << "QEE : assert : " << lit << ", pol = " << pol << ", kind = " << lit.getKind() << std::endl;
if( lit.getKind()==APPLY_UF ){
d_uequalityEngine.assertPredicate(lit, pol, n);
}else{
d_uequalityEngine.assertEquality(lit, pol, n);
}
}
}else{
d_quant_unproc[n] = true;
Trace("qee-debug") << "...add to unprocessed (" << lit.getKind() << ")" << std::endl;
}
}
}
bool QuantEqualityEngine::areUnivDisequalInternal( TNode n1, TNode n2 ) {
return n1!=n2 && d_uequalityEngine.hasTerm( n1 ) && d_uequalityEngine.hasTerm( n2 ) && d_uequalityEngine.areDisequal( n1, n2, false );
}
bool QuantEqualityEngine::areUnivEqualInternal( TNode n1, TNode n2 ) {
return n1==n2 || ( d_uequalityEngine.hasTerm( n1 ) && d_uequalityEngine.hasTerm( n2 ) && d_uequalityEngine.areEqual( n1, n2 ) );
}
TNode QuantEqualityEngine::getUnivRepresentativeInternal( TNode n ) {
if( d_uequalityEngine.hasTerm( n ) ){
return d_uequalityEngine.getRepresentative( n );
}else{
return n;
}
}
bool QuantEqualityEngine::areUnivDisequal( TNode n1, TNode n2 ) {
//TODO: must convert to internal representation
return areUnivDisequalInternal( n1, n2 );
}
bool QuantEqualityEngine::areUnivEqual( TNode n1, TNode n2 ) {
//TODO: must convert to internal representation
return areUnivEqualInternal( n1, n2 );
}
TNode QuantEqualityEngine::getUnivRepresentative( TNode n ) {
//TODO: must convert to internal representation
return getUnivRepresentativeInternal( n );
}
Node QuantEqualityEngine::getFunctionForPredicate( Node f ) {
std::map< Node, Node >::iterator it = d_pred_to_func.find( f );
if( it==d_pred_to_func.end() ){
std::vector< TypeNode > argTypes;
TypeNode tn = f.getType();
for( unsigned i=0; i<(tn.getNumChildren()-1); i++ ){
argTypes.push_back( tn[i] );
}
TypeNode ftn = NodeManager::currentNM()->mkFunctionType( argTypes, d_intType );
std::stringstream ss;
ss << "ee_" << f;
Node op = NodeManager::currentNM()->mkSkolem( ss.str(), ftn, "op created for internal ee" );
d_pred_to_func[f] = op;
return op;
}else{
return it->second;
}
}
Node QuantEqualityEngine::getFunctionAppForPredicateApp( Node n ) {
Assert( n.getKind()==APPLY_UF );
std::vector< Node > children;
children.push_back( getFunctionForPredicate( n.getOperator() ) );
for( unsigned i=0; i<n.getNumChildren(); i++ ){
children.push_back( n[i] );
}
return NodeManager::currentNM()->mkNode( APPLY_UF, children );
}
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