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/********************* */
/*! \file quant_split.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Tim King
** This file is part of the CVC4 project.
** Copyright (c) 2009-2017 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 dynamic quantifiers splitting
**/
#include "theory/quantifiers/quant_split.h"
#include "theory/quantifiers/term_database.h"
#include "theory/quantifiers_engine.h"
#include "theory/quantifiers/first_order_model.h"
#include "options/quantifiers_options.h"
using namespace std;
using namespace CVC4;
using namespace CVC4::kind;
using namespace CVC4::context;
using namespace CVC4::theory;
using namespace CVC4::theory::quantifiers;
QuantDSplit::QuantDSplit( QuantifiersEngine * qe, context::Context* c ) :
QuantifiersModule( qe ), d_added_split( qe->getUserContext() ){
}
/** pre register quantifier */
void QuantDSplit::preRegisterQuantifier( Node q ) {
int max_index = -1;
int max_score = -1;
if( q.getNumChildren()==3 ){
return;
}
Trace("quant-dsplit-debug") << "Check split quantified formula : " << q << std::endl;
for( unsigned i=0; i<q[0].getNumChildren(); i++ ){
TypeNode tn = q[0][i].getType();
if( tn.isDatatype() ){
const Datatype& dt = ((DatatypeType)(tn).toType()).getDatatype();
if( dt.isRecursiveSingleton( tn.toType() ) ){
Trace("quant-dsplit-debug") << "Datatype " << dt.getName() << " is recursive singleton." << std::endl;
}else{
int score = -1;
if( options::quantDynamicSplit()==quantifiers::QUANT_DSPLIT_MODE_AGG ){
score = dt.isInterpretedFinite( tn.toType() ) ? 1 : 0;
}else if( options::quantDynamicSplit()==quantifiers::QUANT_DSPLIT_MODE_DEFAULT ){
//only split if goes from being unhandled -> handled by finite instantiation
// an example is datatypes with uninterpreted sort fields, which are "interpreted finite" but not "finite"
if( !d_quantEngine->isFiniteBound( q, q[0][i] ) ){
score = dt.isInterpretedFinite( tn.toType() ) ? 1 : -1;
}
}
Trace("quant-dsplit-debug") << "Datatype " << dt.getName() << " is score " << score << " (" << dt.isInterpretedFinite( tn.toType() ) << " " << dt.isFinite( tn.toType() ) << ")" << std::endl;
if( score>max_score ){
max_index = i;
max_score = score;
}
}
}
}
if( max_index!=-1 ){
Trace("quant-dsplit-debug") << "Will split at index " << max_index << "." << std::endl;
d_quant_to_reduce[q] = max_index;
d_quantEngine->setOwner( q, this );
}
}
/* whether this module needs to check this round */
bool QuantDSplit::needsCheck( Theory::Effort e ) {
return e>=Theory::EFFORT_FULL && !d_quant_to_reduce.empty();
}
bool QuantDSplit::checkCompleteFor( Node q ) {
// true if we split q
return d_added_split.find( q )!=d_added_split.end();
}
/* Call during quantifier engine's check */
void QuantDSplit::check(Theory::Effort e, QEffort quant_e)
{
//add lemmas ASAP (they are a reduction)
if (quant_e == QEFFORT_CONFLICT)
{
std::vector< Node > lemmas;
for(std::map< Node, int >::iterator it = d_quant_to_reduce.begin(); it != d_quant_to_reduce.end(); ++it) {
Node q = it->first;
if( d_quantEngine->getModel()->isQuantifierAsserted( q ) && d_quantEngine->getModel()->isQuantifierActive( q ) ){
if( d_added_split.find( q )==d_added_split.end() ){
d_added_split.insert( q );
std::vector< Node > bvs;
for( unsigned i=0; i<q[0].getNumChildren(); i++ ){
if( (int)i!=it->second ){
bvs.push_back( q[0][i] );
}
}
std::vector< Node > disj;
disj.push_back( q.negate() );
TNode svar = q[0][it->second];
TypeNode tn = svar.getType();
if( tn.isDatatype() ){
std::vector< Node > cons;
const Datatype& dt = ((DatatypeType)(tn).toType()).getDatatype();
for( unsigned j=0; j<dt.getNumConstructors(); j++ ){
std::vector< Node > vars;
for( unsigned k=0; k<dt[j].getNumArgs(); k++ ){
TypeNode tns = TypeNode::fromType( dt[j][k].getRangeType() );
Node v = NodeManager::currentNM()->mkBoundVar( tns );
vars.push_back( v );
}
std::vector< Node > bvs_cmb;
bvs_cmb.insert( bvs_cmb.end(), bvs.begin(), bvs.end() );
bvs_cmb.insert( bvs_cmb.end(), vars.begin(), vars.end() );
vars.insert( vars.begin(), Node::fromExpr( dt[j].getConstructor() ) );
Node c = NodeManager::currentNM()->mkNode( kind::APPLY_CONSTRUCTOR, vars );
TNode ct = c;
Node body = q[1].substitute( svar, ct );
if( !bvs_cmb.empty() ){
body = NodeManager::currentNM()->mkNode( kind::FORALL, NodeManager::currentNM()->mkNode( kind::BOUND_VAR_LIST, bvs_cmb ), body );
}
cons.push_back( body );
}
Node conc = cons.size()==1 ? cons[0] : NodeManager::currentNM()->mkNode( kind::AND, cons );
disj.push_back( conc );
}else{
Assert( false );
}
lemmas.push_back( disj.size()==1 ? disj[0] : NodeManager::currentNM()->mkNode( kind::OR, disj ) );
}
}
}
//add lemmas to quantifiers engine
for( unsigned i=0; i<lemmas.size(); i++ ){
Trace("quant-dsplit") << "QuantDSplit lemma : " << lemmas[i] << std::endl;
d_quantEngine->addLemma( lemmas[i], false );
}
//d_quant_to_reduce.clear();
}
}
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