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|
/********************* */
/*! \file model_builder.cpp
** \verbatim
** Original author: ajreynol
** Major contributors: none
** Minor contributors (to current version): mdeters
** This file is part of the CVC4 prototype.
** Copyright (c) 2009-2012 New York University and The University of Iowa
** See the file COPYING in the top-level source directory for licensing
** information.\endverbatim
**
** \brief Implementation of model builder class
**/
#include "theory/quantifiers/model_engine.h"
#include "theory/theory_engine.h"
#include "theory/uf/equality_engine.h"
#include "theory/uf/theory_uf.h"
#include "theory/uf/theory_uf_model.h"
#include "theory/uf/theory_uf_instantiator.h"
#include "theory/uf/theory_uf_strong_solver.h"
#include "theory/arrays/theory_arrays_model.h"
#include "theory/quantifiers/first_order_model.h"
#include "theory/quantifiers/term_database.h"
#include "theory/quantifiers/model_builder.h"
#include "theory/quantifiers/quantifiers_attributes.h"
#include "theory/quantifiers/inst_gen.h"
using namespace std;
using namespace CVC4;
using namespace CVC4::kind;
using namespace CVC4::context;
using namespace CVC4::theory;
using namespace CVC4::theory::quantifiers;
ModelEngineBuilder::ModelEngineBuilder( context::Context* c, QuantifiersEngine* qe ) :
TheoryEngineModelBuilder( qe->getTheoryEngine() ),
d_qe( qe ), d_curr_model( c, NULL ){
d_considerAxioms = true;
}
void ModelEngineBuilder::processBuildModel( TheoryModel* m, bool fullModel ) {
FirstOrderModel* fm = (FirstOrderModel*)m;
if( fullModel ){
Assert( d_curr_model==fm );
//update models
for( std::map< Node, uf::UfModelTree >::iterator it = fm->d_uf_model_tree.begin(); it != fm->d_uf_model_tree.end(); ++it ){
it->second.update( fm );
Trace("model-func") << "ModelEngineBuilder: Make function value from tree " << it->first << std::endl;
//construct function values
fm->d_uf_models[ it->first ] = it->second.getFunctionValue( "$x" );
}
TheoryEngineModelBuilder::processBuildModel( m, fullModel );
}else{
d_curr_model = fm;
//build model for relevant symbols contained in quantified formulas
d_addedLemmas = 0;
//only construct first order model if optUseModel() is true
if( optUseModel() ){
if( optUseModel() ){
//check if any quantifiers are un-initialized
for( int i=0; i<fm->getNumAssertedQuantifiers(); i++ ){
Node f = fm->getAssertedQuantifier( i );
d_addedLemmas += initializeQuantifier( f );
}
}
if( d_addedLemmas>0 ){
Trace("model-engine") << "Initialize, Added Lemmas = " << d_addedLemmas << std::endl;
}else{
//initialize model
fm->initialize( d_considerAxioms );
//analyze the functions
Trace("model-engine-debug") << "Analyzing model..." << std::endl;
analyzeModel( fm );
//analyze the quantifiers
Trace("model-engine-debug") << "Analyzing quantifiers..." << std::endl;
d_quant_sat.clear();
d_uf_prefs.clear();
analyzeQuantifiers( fm );
//if applicable, find exceptions
if( optInstGen() ){
//now, see if we know that any exceptions via InstGen exist
Trace("model-engine-debug") << "Perform InstGen techniques for quantifiers..." << std::endl;
for( int i=0; i<fm->getNumAssertedQuantifiers(); i++ ){
Node f = fm->getAssertedQuantifier( i );
if( isQuantifierActive( f ) ){
d_addedLemmas += doInstGen( fm, f );
if( optOneQuantPerRoundInstGen() && d_addedLemmas>0 ){
break;
}
}
}
if( Trace.isOn("model-engine") ){
if( d_addedLemmas>0 ){
Trace("model-engine") << "InstGen, added lemmas = " << d_addedLemmas << std::endl;
}else{
Trace("model-engine") << "No InstGen lemmas..." << std::endl;
}
}
}
if( d_addedLemmas==0 ){
//if no immediate exceptions, build the model
// this model will be an approximation that will need to be tested via exhaustive instantiation
Trace("model-engine-debug") << "Building model..." << std::endl;
constructModel( fm );
}
}
}
}
}
int ModelEngineBuilder::initializeQuantifier( Node f ){
if( d_quant_init.find( f )==d_quant_init.end() ){
d_quant_init[f] = true;
Debug("inst-fmf-init") << "Initialize " << f << std::endl;
//add the model basis instantiation
// This will help produce the necessary information for model completion.
// We do this by extending distinguish ground assertions (those
// containing terms with "model basis" attribute) to hold for all cases.
////first, check if any variables are required to be equal
//for( std::map< Node, bool >::iterator it = d_quantEngine->d_phase_reqs[f].begin();
// it != d_quantEngine->d_phase_reqs[f].end(); ++it ){
// Node n = it->first;
// if( n.getKind()==EQUAL && n[0].getKind()==INST_CONSTANT && n[1].getKind()==INST_CONSTANT ){
// Notice() << "Unhandled phase req: " << n << std::endl;
// }
//}
std::vector< Node > vars;
std::vector< Node > terms;
for( int j=0; j<(int)f[0].getNumChildren(); j++ ){
Node ic = d_qe->getTermDatabase()->getInstantiationConstant( f, j );
Node t = d_qe->getTermDatabase()->getModelBasisTerm( ic.getType() );
vars.push_back( f[0][j] );
terms.push_back( t );
//calculate the basis match for f
d_quant_basis_match[f].set( ic, t);
}
++(d_statistics.d_num_quants_init);
if( optInstGen() ){
//add model basis instantiation
if( d_qe->addInstantiation( f, vars, terms ) ){
return 1;
}else{
//shouldn't happen usually, but will occur if x != y is a required literal for f.
//Notice() << "No model basis for " << f << std::endl;
++(d_statistics.d_num_quants_init_fail);
}
}
}
return 0;
}
void ModelEngineBuilder::analyzeModel( FirstOrderModel* fm ){
d_uf_model_constructed.clear();
//determine if any functions are constant
for( std::map< Node, uf::UfModelTree >::iterator it = fm->d_uf_model_tree.begin(); it != fm->d_uf_model_tree.end(); ++it ){
Node op = it->first;
for( size_t i=0; i<fm->d_uf_terms[op].size(); i++ ){
Node n = fm->d_uf_terms[op][i];
if( !n.getAttribute(NoMatchAttribute()) ){
Node v = fm->getRepresentative( n );
if( i==0 ){
d_uf_prefs[op].d_const_val = v;
}else if( v!=d_uf_prefs[op].d_const_val ){
d_uf_prefs[op].d_const_val = Node::null();
break;
}
}
}
if( !d_uf_prefs[op].d_const_val.isNull() ){
fm->d_uf_model_gen[op].setDefaultValue( d_uf_prefs[op].d_const_val );
fm->d_uf_model_gen[op].makeModel( fm, it->second );
Debug("fmf-model-cons") << "Function " << op << " is the constant function ";
fm->printRepresentativeDebug( "fmf-model-cons", d_uf_prefs[op].d_const_val );
Debug("fmf-model-cons") << std::endl;
d_uf_model_constructed[op] = true;
}else{
d_uf_model_constructed[op] = false;
}
}
}
void ModelEngineBuilder::constructModel( FirstOrderModel* fm ){
//build model for UF
for( std::map< Node, uf::UfModelTree >::iterator it = fm->d_uf_model_tree.begin(); it != fm->d_uf_model_tree.end(); ++it ){
constructModelUf( fm, it->first );
}
/*
//build model for arrays
for( std::map< Node, arrays::ArrayModel >::iterator it = fm->d_array_model.begin(); it != fm->d_array_model.end(); ++it ){
//consult the model basis select term
// i.e. the default value for array A is the value of select( A, e ), where e is the model basis term
TypeNode tn = it->first.getType();
Node selModelBasis = NodeManager::currentNM()->mkNode( SELECT, it->first, fm->getTermDatabase()->getModelBasisTerm( tn[0] ) );
it->second.setDefaultValue( fm->getRepresentative( selModelBasis ) );
}
*/
Trace("model-engine-debug") << "Done building models." << std::endl;
}
void ModelEngineBuilder::constructModelUf( FirstOrderModel* fm, Node op ){
if( optReconsiderFuncConstants() ){
//reconsider constant functions that weren't necessary
if( d_uf_model_constructed[op] ){
if( d_uf_prefs[op].d_reconsiderModel ){
//if we are allowed to reconsider default value, then see if the default value can be improved
Node v = d_uf_prefs[op].d_const_val;
if( d_uf_prefs[op].d_value_pro_con[0][v].empty() ){
Debug("fmf-model-cons-debug") << "Consider changing the default value for " << op << std::endl;
fm->d_uf_model_tree[op].clear();
fm->d_uf_model_gen[op].clear();
d_uf_model_constructed[op] = false;
}
}
}
}
if( !d_uf_model_constructed[op] ){
//construct the model for the uninterpretted function/predicate
bool setDefaultVal = true;
Node defaultTerm = d_qe->getTermDatabase()->getModelBasisOpTerm( op );
Debug("fmf-model-cons") << "Construct model for " << op << "..." << std::endl;
//set the values in the model
for( size_t i=0; i<fm->d_uf_terms[op].size(); i++ ){
Node n = fm->d_uf_terms[op][i];
if( !n.getAttribute(NoMatchAttribute()) || n.getAttribute(ModelBasisArgAttribute())==1 ){
Node v = fm->getRepresentative( n );
//if this assertion did not help the model, just consider it ground
//set n = v in the model tree
Debug("fmf-model-cons") << " Set " << n << " = ";
fm->printRepresentativeDebug( "fmf-model-cons", v );
Debug("fmf-model-cons") << std::endl;
//set it as ground value
fm->d_uf_model_gen[op].setValue( fm, n, v );
if( fm->d_uf_model_gen[op].optUsePartialDefaults() ){
//also set as default value if necessary
//if( n.getAttribute(ModelBasisArgAttribute())==1 && !d_term_pro_con[0][n].empty() ){
if( shouldSetDefaultValue( n ) ){
fm->d_uf_model_gen[op].setValue( fm, n, v, false );
if( n==defaultTerm ){
//incidentally already set, we will not need to find a default value
setDefaultVal = false;
}
}
}else{
if( n==defaultTerm ){
fm->d_uf_model_gen[op].setValue( fm, n, v, false );
//incidentally already set, we will not need to find a default value
setDefaultVal = false;
}
}
}
}
//set the overall default value if not set already (is this necessary??)
if( setDefaultVal ){
Debug("fmf-model-cons") << " Choose default value..." << std::endl;
//chose defaultVal based on heuristic, currently the best ratio of "pro" responses
Node defaultVal = d_uf_prefs[op].getBestDefaultValue( defaultTerm, fm );
Assert( !defaultVal.isNull() );
fm->d_uf_model_gen[op].setValue( fm, defaultTerm, defaultVal, false );
}
Debug("fmf-model-cons") << " Making model...";
fm->d_uf_model_gen[op].makeModel( fm, fm->d_uf_model_tree[op] );
d_uf_model_constructed[op] = true;
Debug("fmf-model-cons") << " Finished constructing model for " << op << "." << std::endl;
}
}
bool ModelEngineBuilder::optUseModel() {
return options::fmfModelBasedInst();
}
bool ModelEngineBuilder::optInstGen(){
return options::fmfInstGen();
}
bool ModelEngineBuilder::optOneQuantPerRoundInstGen(){
return options::fmfInstGenOneQuantPerRound();
}
bool ModelEngineBuilder::optReconsiderFuncConstants(){
return false;
}
void ModelEngineBuilder::setEffort( int effort ){
d_considerAxioms = effort>=1;
}
ModelEngineBuilder::Statistics::Statistics():
d_pre_sat_quant("ModelEngineBuilder::Status_quant_pre_sat", 0),
d_pre_nsat_quant("ModelEngineBuilder::Status_quant_pre_non_sat", 0),
d_num_quants_init("ModelEngine::Num_Quants", 0 ),
d_num_quants_init_fail("ModelEngine::Num_Quants_No_Basis", 0 )
{
StatisticsRegistry::registerStat(&d_pre_sat_quant);
StatisticsRegistry::registerStat(&d_pre_nsat_quant);
StatisticsRegistry::registerStat(&d_num_quants_init);
StatisticsRegistry::registerStat(&d_num_quants_init_fail);
}
ModelEngineBuilder::Statistics::~Statistics(){
StatisticsRegistry::unregisterStat(&d_pre_sat_quant);
StatisticsRegistry::unregisterStat(&d_pre_nsat_quant);
StatisticsRegistry::unregisterStat(&d_num_quants_init);
StatisticsRegistry::unregisterStat(&d_num_quants_init_fail);
}
bool ModelEngineBuilder::isQuantifierActive( Node f ){
return ( d_considerAxioms || !f.getAttribute(AxiomAttribute()) ) && d_quant_sat.find( f )==d_quant_sat.end();
}
void ModelEngineBuilderDefault::analyzeQuantifiers( FirstOrderModel* fm ){
d_quant_selection_lit.clear();
d_quant_selection_lit_candidates.clear();
d_quant_selection_lit_terms.clear();
d_term_selection_lit.clear();
d_op_selection_terms.clear();
//analyze each quantifier
for( int i=0; i<(int)fm->getNumAssertedQuantifiers(); i++ ){
Node f = fm->getAssertedQuantifier( i );
if( isQuantifierActive( f ) ){
analyzeQuantifier( fm, f );
}
}
}
void ModelEngineBuilderDefault::analyzeQuantifier( FirstOrderModel* fm, Node f ){
Debug("fmf-model-prefs") << "Analyze quantifier " << f << std::endl;
//the pro/con preferences for this quantifier
std::vector< Node > pro_con[2];
//the terms in the selection literal we choose
std::vector< Node > selectionLitTerms;
//for each asserted quantifier f,
// - determine selection literals
// - check which function/predicates have good and bad definitions for satisfying f
for( std::map< Node, bool >::iterator it = d_qe->d_phase_reqs[f].begin();
it != d_qe->d_phase_reqs[f].end(); ++it ){
//the literal n is phase-required for quantifier f
Node n = it->first;
Node gn = d_qe->getTermDatabase()->getModelBasis( f, n );
Debug("fmf-model-req") << " Req: " << n << " -> " << it->second << std::endl;
bool value;
//if the corresponding ground abstraction literal has a SAT value
if( d_qe->getValuation().hasSatValue( gn, value ) ){
//collect the non-ground uf terms that this literal contains
// and compute if all of the symbols in this literal have
// constant definitions.
bool isConst = true;
std::vector< Node > uf_terms;
if( n.hasAttribute(InstConstantAttribute()) ){
isConst = false;
if( gn.getKind()==APPLY_UF ){
uf_terms.push_back( gn );
isConst = !d_uf_prefs[gn.getOperator()].d_const_val.isNull();
}else if( gn.getKind()==EQUAL ){
isConst = true;
for( int j=0; j<2; j++ ){
if( n[j].hasAttribute(InstConstantAttribute()) ){
if( n[j].getKind()==APPLY_UF &&
fm->d_uf_model_tree.find( gn[j].getOperator() )!=fm->d_uf_model_tree.end() ){
uf_terms.push_back( gn[j] );
isConst = isConst && !d_uf_prefs[ gn[j].getOperator() ].d_const_val.isNull();
}else{
isConst = false;
}
}
}
}
}
//check if the value in the SAT solver matches the preference according to the quantifier
int pref = 0;
if( value!=it->second ){
//we have a possible selection literal
bool selectLit = d_quant_selection_lit[f].isNull();
bool selectLitConstraints = true;
//it is a constantly defined selection literal : the quantifier is sat
if( isConst ){
selectLit = selectLit || d_quant_sat.find( f )==d_quant_sat.end();
d_quant_sat[f] = true;
//check if choosing this literal would add any additional constraints to default definitions
selectLitConstraints = false;
for( int j=0; j<(int)uf_terms.size(); j++ ){
Node op = uf_terms[j].getOperator();
if( d_uf_prefs[op].d_reconsiderModel ){
selectLitConstraints = true;
}
}
if( !selectLitConstraints ){
selectLit = true;
}
}
//see if we wish to choose this as a selection literal
d_quant_selection_lit_candidates[f].push_back( value ? n : n.notNode() );
if( selectLit ){
Trace("inst-gen-debug") << "Choose selection literal " << gn << std::endl;
d_quant_selection_lit[f] = value ? n : n.notNode();
selectionLitTerms.clear();
selectionLitTerms.insert( selectionLitTerms.begin(), uf_terms.begin(), uf_terms.end() );
if( !selectLitConstraints ){
break;
}
}
pref = 1;
}else{
pref = -1;
}
//if we are not yet SAT, so we will add to preferences
if( d_quant_sat.find( f )==d_quant_sat.end() ){
Debug("fmf-model-prefs") << " It is " << ( pref==1 ? "pro" : "con" );
Debug("fmf-model-prefs") << " the definition of " << n << std::endl;
for( int j=0; j<(int)uf_terms.size(); j++ ){
pro_con[ pref==1 ? 0 : 1 ].push_back( uf_terms[j] );
}
}
}
}
//process information about selection literal for f
if( !d_quant_selection_lit[f].isNull() ){
d_quant_selection_lit_terms[f].insert( d_quant_selection_lit_terms[f].begin(), selectionLitTerms.begin(), selectionLitTerms.end() );
for( int i=0; i<(int)selectionLitTerms.size(); i++ ){
d_term_selection_lit[ selectionLitTerms[i] ] = d_quant_selection_lit[f];
d_op_selection_terms[ selectionLitTerms[i].getOperator() ].push_back( selectionLitTerms[i] );
}
}else{
Trace("inst-gen-warn") << "WARNING: " << f << " has no selection literals (is the body of f clausified?)" << std::endl;
}
//process information about requirements and preferences of quantifier f
if( d_quant_sat.find( f )!=d_quant_sat.end() ){
Debug("fmf-model-prefs") << " * Constant SAT due to definition of ops: ";
for( int i=0; i<(int)selectionLitTerms.size(); i++ ){
Debug("fmf-model-prefs") << selectionLitTerms[i] << " ";
d_uf_prefs[ selectionLitTerms[i].getOperator() ].d_reconsiderModel = false;
}
Debug("fmf-model-prefs") << std::endl;
++(d_statistics.d_pre_sat_quant);
}else{
++(d_statistics.d_pre_nsat_quant);
//note quantifier's value preferences to models
for( int k=0; k<2; k++ ){
for( int j=0; j<(int)pro_con[k].size(); j++ ){
Node op = pro_con[k][j].getOperator();
Node r = fm->getRepresentative( pro_con[k][j] );
d_uf_prefs[op].setValuePreference( f, pro_con[k][j], r, k==0 );
}
}
}
}
int ModelEngineBuilderDefault::doInstGen( FirstOrderModel* fm, Node f ){
int addedLemmas = 0;
//we wish to add all known exceptions to our selection literal for f. this will help to refine our current model.
//This step is advantageous over exhaustive instantiation, since we are adding instantiations that involve model basis terms,
// effectively acting as partial instantiations instead of pointwise instantiations.
if( !d_quant_selection_lit[f].isNull() ){
Trace("inst-gen") << "Do Inst-Gen for " << f << std::endl;
for( size_t i=0; i<d_quant_selection_lit_candidates[f].size(); i++ ){
bool phase = d_quant_selection_lit_candidates[f][i].getKind()!=NOT;
Node lit = d_quant_selection_lit_candidates[f][i].getKind()==NOT ? d_quant_selection_lit_candidates[f][i][0] : d_quant_selection_lit_candidates[f][i];
Assert( lit.hasAttribute(InstConstantAttribute()) );
std::vector< Node > tr_terms;
if( lit.getKind()==APPLY_UF ){
//only match predicates that are contrary to this one, use literal matching
Node eq = NodeManager::currentNM()->mkNode( IFF, lit, !phase ? fm->d_true : fm->d_false );
d_qe->getTermDatabase()->setInstantiationConstantAttr( eq, f );
tr_terms.push_back( eq );
}else if( lit.getKind()==EQUAL ){
//collect trigger terms
for( int j=0; j<2; j++ ){
if( lit[j].hasAttribute(InstConstantAttribute()) ){
if( lit[j].getKind()==APPLY_UF ){
tr_terms.push_back( lit[j] );
}else{
tr_terms.clear();
break;
}
}
}
if( tr_terms.size()==1 && !phase ){
//equality between a function and a ground term, use literal matching
tr_terms.clear();
tr_terms.push_back( lit );
}
}
//if applicable, try to add exceptions here
if( !tr_terms.empty() ){
//make a trigger for these terms, add instantiations
inst::Trigger* tr = inst::Trigger::mkTrigger( d_qe, f, tr_terms );
//Notice() << "Trigger = " << (*tr) << std::endl;
tr->resetInstantiationRound();
tr->reset( Node::null() );
//d_qe->d_optInstMakeRepresentative = false;
//d_qe->d_optMatchIgnoreModelBasis = true;
addedLemmas += tr->addInstantiations( d_quant_basis_match[f] );
}
}
}
return addedLemmas;
}
bool ModelEngineBuilderDefault::shouldSetDefaultValue( Node n ){
return n.hasAttribute(ModelBasisArgAttribute()) && n.getAttribute(ModelBasisArgAttribute())==1;
}
void ModelEngineBuilderInstGen::analyzeQuantifiers( FirstOrderModel* fm ){
//for new inst gen
d_quant_selection_formula.clear();
d_term_selected.clear();
//analyze each quantifier
for( int i=0; i<(int)fm->getNumAssertedQuantifiers(); i++ ){
Node f = fm->getAssertedQuantifier( i );
if( isQuantifierActive( f ) ){
analyzeQuantifier( fm, f );
}
}
//analyze each partially instantiated quantifier
for( std::map< Node, Node >::iterator it = d_sub_quant_parent.begin(); it != d_sub_quant_parent.end(); ++it ){
Node fp = getParentQuantifier( it->first );
if( isQuantifierActive( fp ) ){
analyzeQuantifier( fm, it->first );
}
}
}
void ModelEngineBuilderInstGen::analyzeQuantifier( FirstOrderModel* fm, Node f ){
//determine selection formula, set terms in selection formula as being selected
Node s = getSelectionFormula( d_qe->getTermDatabase()->getCounterexampleBody( f ),
d_qe->getTermDatabase()->getModelBasisBody( f ), true, 0 );
Trace("sel-form") << "Selection formula for " << f << " is " << s << std::endl;
if( !s.isNull() ){
d_quant_selection_formula[f] = s;
Node gs = d_qe->getTermDatabase()->getModelBasis( f, s );
setSelectedTerms( gs );
}
}
int ModelEngineBuilderInstGen::doInstGen( FirstOrderModel* fm, Node f ){
int addedLemmas = 0;
//we wish to add all known exceptions to our selection literal for f. this will help to refine our current model.
//This step is advantageous over exhaustive instantiation, since we are adding instantiations that involve model basis terms,
// effectively acting as partial instantiations instead of pointwise instantiations.
if( !d_quant_selection_formula[f].isNull() ){
//first, try on sub quantifiers
for( size_t i=0; i<d_sub_quants[f].size(); i++ ){
addedLemmas += doInstGen( fm, d_sub_quants[f][i] );
}
if( addedLemmas>0 ){
return addedLemmas;
}else{
Node fp = getParentQuantifier( f );
Trace("inst-gen") << "Do Inst-Gen for " << f << std::endl;
Trace("inst-gen-debug") << "Calculate inst-gen instantiations..." << std::endl;
//get all possible values of selection formula
InstGenProcess igp( d_quant_selection_formula[f] );
igp.calculateMatches( d_qe, f );
Trace("inst-gen-debug") << "Add inst-gen instantiations..." << std::endl;
for( int i=0; i<igp.getNumMatches(); i++ ){
//if the match is not already true in the model
if( igp.getMatchValue( i )!=fm->d_true ){
InstMatch m;
igp.getMatch( d_qe->getEqualityQuery(), i, m );
//we only consider matches that are non-empty
// matches that are empty should trigger other instances that are non-empty
if( !m.empty() ){
bool addInst = false;
//translate to be in terms match in terms of fp
InstMatch mp;
getParentQuantifierMatch( mp, fp, m, f );
//if this is a partial instantion
if( !m.isComplete( f ) ){
Trace("inst-gen-debug") << "- partial inst" << std::endl;
//if the instantiation does not yet exist
if( d_sub_quant_inst_trie[fp].addInstMatch( d_qe, fp, mp, true, NULL ) ){
//get the partial instantiation pf
Node pf = d_qe->getInstantiation( fp, mp );
Trace("inst-gen-pi") << "Partial instantiation of " << f << std::endl;
Trace("inst-gen-pi") << " " << pf << std::endl;
d_sub_quants[ f ].push_back( pf );
d_sub_quant_inst[ pf ] = InstMatch( &mp );
d_sub_quant_parent[ pf ] = fp;
mp.add( d_quant_basis_match[ fp ] );
addInst = true;
}
}else{
addInst = true;
}
if( addInst ){
Trace("inst-gen-debug") << "- complete inst" << std::endl;
//otherwise, get instantiation and add ground instantiation in terms of root parent
if( d_qe->addInstantiation( fp, mp ) ){
addedLemmas++;
}
}
}
}
}
if( addedLemmas==0 ){
//all sub quantifiers must be satisfied as well
bool subQuantSat = true;
for( size_t i=0; i<d_sub_quants[f].size(); i++ ){
if( d_quant_sat.find( d_sub_quants[f][i] )==d_quant_sat.end() ){
subQuantSat = false;
break;
}
}
if( subQuantSat ){
d_quant_sat[ f ] = true;
}
}
Trace("inst-gen") << " -> added lemmas = " << addedLemmas << std::endl;
}
}
return addedLemmas;
}
bool ModelEngineBuilderInstGen::shouldSetDefaultValue( Node n ){
return d_term_selected.find( n )!=d_term_selected.end();
}
//if possible, returns a formula n' such that ( n' <=> polarity ) => ( n <=> polarity ), and ( n' <=> polarity ) is true in the current context,
// and NULL otherwise
Node ModelEngineBuilderInstGen::getSelectionFormula( Node fn, Node n, bool polarity, int useOption ){
if( n.getKind()==NOT ){
Node nn = getSelectionFormula( fn[0], n[0], !polarity, useOption );
if( !nn.isNull() ){
return nn.negate();
}
}else if( n.getKind()==OR || n.getKind()==IMPLIES || n.getKind()==AND ){
//whether we only need to find one or all
bool posPol = (( n.getKind()==OR || n.getKind()==IMPLIES ) && polarity ) || ( n.getKind()==AND && !polarity );
std::vector< Node > children;
for( int i=0; i<(int)n.getNumChildren(); i++ ){
Node fnc = ( i==0 && fn.getKind()==IMPLIES ) ? fn[i].negate() : fn[i];
Node nc = ( i==0 && n.getKind()==IMPLIES ) ? n[i].negate() : n[i];
Node nn = getSelectionFormula( fnc, nc, polarity, useOption );
if( nn.isNull()!=posPol ){ //TODO: may want to weaken selection formula
return nn;
}
children.push_back( nn );
}
if( !posPol ){
return NodeManager::currentNM()->mkNode( n.getKind()==AND ? AND : OR, children );
}
}else if( n.getKind()==ITE ){
Node nn;
Node nc[2];
//get selection formula for the
for( int i=0; i<2; i++ ){
nn = getSelectionFormula( i==0 ? fn[0] : fn[0].negate(), i==0 ? n[0] : n[0].negate(), true, useOption );
nc[i] = getSelectionFormula( fn[i+1], n[i+1], polarity, useOption );
if( !nn.isNull() && !nc[i].isNull() ){
return NodeManager::currentNM()->mkNode( AND, nn, nc[i] );
}
}
if( !nc[0].isNull() && !nc[1].isNull() ){
return NodeManager::currentNM()->mkNode( AND, nc[0], nc[1] );
}
}else if( n.getKind()==IFF || n.getKind()==XOR ){
bool opPol = polarity ? n.getKind()==XOR : n.getKind()==IFF;
for( int p=0; p<2; p++ ){
Node nn[2];
for( int i=0; i<2; i++ ){
bool pol = i==0 ? p==0 : ( opPol ? p!=0 : p==0 );
nn[i] = getSelectionFormula( pol ? fn[i] : fn[i].negate(), pol ? n[i] : n[i].negate(), true, useOption );
if( nn[i].isNull() ){
break;
}
}
if( !nn[0].isNull() && !nn[1].isNull() ){
return NodeManager::currentNM()->mkNode( AND, nn[0], nn[1] );
}
}
}else{
//literal case
//first, check if it is a usable selection literal
if( isUsableSelectionLiteral( n, useOption ) ){
bool value;
if( d_qe->getValuation().hasSatValue( n, value ) ){
if( value==polarity ){
return fn;
}
}
}
}
return Node::null();
}
void ModelEngineBuilderInstGen::setSelectedTerms( Node s ){
//if it is apply uf and has model basis arguments, then mark term as being "selected"
if( s.getKind()==APPLY_UF ){
Assert( s.hasAttribute(ModelBasisArgAttribute()) );
if( !s.hasAttribute(ModelBasisArgAttribute()) ) std::cout << "no mba!! " << s << std::endl;
if( s.getAttribute(ModelBasisArgAttribute())==1 ){
d_term_selected[ s ] = true;
Trace("sel-form") << " " << s << " is a selected term." << std::endl;
}
}
for( int i=0; i<(int)s.getNumChildren(); i++ ){
setSelectedTerms( s[i] );
}
}
bool ModelEngineBuilderInstGen::isUsableSelectionLiteral( Node n, int useOption ){
if( n.getKind()==FORALL ){
return false;
}else if( n.getKind()!=APPLY_UF ){
for( int i=0; i<(int)n.getNumChildren(); i++ ){
//if it is a variable, then return false
if( n[i].getAttribute(ModelBasisAttribute()) ){
return false;
}
}
}
for( int i=0; i<(int)n.getNumChildren(); i++ ){
if( !isUsableSelectionLiteral( n[i], useOption ) ){
return false;
}
}
return true;
}
Node ModelEngineBuilderInstGen::getParentQuantifier( Node f ){
std::map< Node, Node >::iterator it = d_sub_quant_parent.find( f );
if( it==d_sub_quant_parent.end() ){
return f;
}else{
return getParentQuantifier( it->second );
}
}
void ModelEngineBuilderInstGen::getParentQuantifierMatch( InstMatch& mp, Node fp, InstMatch& m, Node f ){
int counter = 0;
for( size_t i=0; i<fp[0].getNumChildren(); i++ ){
Node icp = d_qe->getTermDatabase()->getInstantiationConstant( fp, i );
if( fp[0][i]==f[0][counter] ){
Node ic = d_qe->getTermDatabase()->getInstantiationConstant( f, counter );
Node n = m.getValue( ic );
if( !n.isNull() ){
mp.setMatch( d_qe->getEqualityQuery(), icp, n );
}
counter++;
}
}
mp.add( d_sub_quant_inst[f] );
}
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