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/********************* */
/*! \file local_theory_ext.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Paul Meng
** 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 local theory ext utilities
**/
#include "theory/quantifiers/local_theory_ext.h"
#include "theory/quantifiers/term_database.h"
#include "theory/quantifiers/term_util.h"
#include "theory/quantifiers_engine.h"
#include "theory/quantifiers/first_order_model.h"
using namespace std;
using namespace CVC4;
using namespace CVC4::kind;
using namespace CVC4::context;
using namespace CVC4::theory;
using namespace CVC4::theory::quantifiers;
LtePartialInst::LtePartialInst( QuantifiersEngine * qe, context::Context* c ) :
QuantifiersModule( qe ), d_wasInvoked( false ), d_needsCheck( false ){
}
/** add quantifier */
void LtePartialInst::preRegisterQuantifier( Node q ) {
if( !q.getAttribute(LtePartialInstAttribute()) ){
if( d_do_inst.find( q )!=d_do_inst.end() ){
if( d_do_inst[q] ){
d_lte_asserts.push_back( q );
d_quantEngine->setOwner( q, this );
}
}else{
d_vars[q].clear();
d_pat_var_order[q].clear();
//check if this quantified formula is eligible for partial instantiation
std::map< Node, bool > vars;
for( unsigned i=0; i<q[0].getNumChildren(); i++ ){
vars[q[0][i]] = false;
}
getEligibleInstVars( q[1], vars );
//instantiate only if we would force ground instances
std::map< Node, int > var_order;
bool doInst = true;
for( unsigned i=0; i<q[0].getNumChildren(); i++ ){
if( vars[q[0][i]] ){
d_vars[q].push_back( q[0][i] );
var_order[q[0][i]] = i;
}else{
Trace("lte-partial-inst-debug") << "...do not consider, variable " << q[0][i] << " was not found in correct position in body." << std::endl;
doInst = false;
break;
}
}
if( doInst ){
//also needs patterns
if( q.getNumChildren()==3 && q[2].getNumChildren()==1 ){
for( unsigned i=0; i<q[2][0].getNumChildren(); i++ ){
Node pat = q[2][0][i];
if( pat.getKind()==APPLY_UF ){
for( unsigned j=0; j<pat.getNumChildren(); j++ ){
if( !addVariableToPatternList( pat[j], d_pat_var_order[q], var_order ) ){
doInst = false;
}
}
}else if( !addVariableToPatternList( pat, d_pat_var_order[q], var_order ) ){
doInst = false;
}
if( !doInst ){
Trace("lte-partial-inst-debug") << "...do not consider, cannot resolve pattern : " << pat << std::endl;
break;
}
}
}else{
Trace("lte-partial-inst-debug") << "...do not consider (must have exactly one pattern)." << std::endl;
}
}
Trace("lte-partial-inst") << "LTE: ...will " << ( doInst ? "" : "not ") << "instantiate " << q << std::endl;
d_do_inst[q] = doInst;
if( doInst ){
d_lte_asserts.push_back( q );
d_needsCheck = true;
d_quantEngine->setOwner( q, this );
}
}
}
}
bool LtePartialInst::addVariableToPatternList( Node v, std::vector< int >& pat_var_order, std::map< Node, int >& var_order ) {
std::map< Node, int >::iterator it = var_order.find( v );
if( it==var_order.end() ){
return false;
}else if( std::find( pat_var_order.begin(), pat_var_order.end(), it->second )!=pat_var_order.end() ){
return false;
}else{
pat_var_order.push_back( it->second );
return true;
}
}
void LtePartialInst::getEligibleInstVars( Node n, std::map< Node, bool >& vars ) {
if( n.getKind()==APPLY_UF && !n.getType().isBoolean() ){
for( unsigned i=0; i<n.getNumChildren(); i++ ){
if( vars.find( n[i] )!=vars.end() ){
vars[n[i]] = true;
}
}
}
for( unsigned i=0; i<n.getNumChildren(); i++ ){
getEligibleInstVars( n[i], vars );
}
}
/* whether this module needs to check this round */
bool LtePartialInst::needsCheck( Theory::Effort e ) {
return e>=Theory::EFFORT_FULL && d_needsCheck;
}
/* Call during quantifier engine's check */
void LtePartialInst::check(Theory::Effort e, QEffort quant_e)
{
//flush lemmas ASAP (they are a reduction)
if (quant_e == QEFFORT_CONFLICT && d_needsCheck)
{
std::vector< Node > lemmas;
getInstantiations( lemmas );
//add lemmas to quantifiers engine
for( unsigned i=0; i<lemmas.size(); i++ ){
d_quantEngine->addLemma( lemmas[i], false );
}
d_needsCheck = false;
}
}
void LtePartialInst::reset() {
d_reps.clear();
eq::EqualityEngine* ee = d_quantEngine->getActiveEqualityEngine();
eq::EqClassesIterator eqcs_i = eq::EqClassesIterator( ee );
while( !eqcs_i.isFinished() ){
TNode r = (*eqcs_i);
TypeNode tn = r.getType();
d_reps[tn].push_back( r );
++eqcs_i;
}
}
/** get instantiations */
void LtePartialInst::getInstantiations( std::vector< Node >& lemmas ) {
Trace("lte-partial-inst") << "LTE : get instantiations, # quant = " << d_lte_asserts.size() << std::endl;
reset();
for( unsigned i=0; i<d_lte_asserts.size(); i++ ){
Node q = d_lte_asserts[i];
Assert( d_do_inst.find( q )!=d_do_inst.end() && d_do_inst[q] );
if( d_inst.find( q )==d_inst.end() ){
Trace("lte-partial-inst") << "LTE : Get partial instantiations for " << q << "..." << std::endl;
d_inst[q] = true;
Assert( !d_vars[q].empty() );
//make bound list
Node bvl;
std::vector< Node > bvs;
for( unsigned j=0; j<q[0].getNumChildren(); j++ ){
if( std::find( d_vars[q].begin(), d_vars[q].end(), q[0][j] )==d_vars[q].end() ){
bvs.push_back( q[0][j] );
}
}
if( !bvs.empty() ){
bvl = NodeManager::currentNM()->mkNode( BOUND_VAR_LIST, bvs );
}
std::vector< Node > conj;
std::vector< Node > terms;
std::vector< TypeNode > types;
for( unsigned j=0; j<d_vars[q].size(); j++ ){
types.push_back( d_vars[q][j].getType() );
terms.push_back( Node::null() );
}
getPartialInstantiations( conj, q, bvl, d_vars[q], terms, types, NULL, 0, 0, 0 );
Assert( !conj.empty() );
lemmas.push_back( NodeManager::currentNM()->mkNode( OR, q.negate(), conj.size()==1 ? conj[0] : NodeManager::currentNM()->mkNode( AND, conj ) ) );
d_wasInvoked = true;
}
}
}
void LtePartialInst::getPartialInstantiations( std::vector< Node >& conj, Node q, Node bvl,
std::vector< Node >& vars, std::vector< Node >& terms, std::vector< TypeNode >& types, TermArgTrie * curr,
unsigned pindex, unsigned paindex, unsigned iindex ){
if( iindex==vars.size() ){
Node body = q[1].substitute( vars.begin(), vars.end(), terms.begin(), terms.end() );
if( bvl.isNull() ){
conj.push_back( body );
Trace("lte-partial-inst") << " - ground conjunct : " << body << std::endl;
}else{
Node nq;
if( q.getNumChildren()==3 ){
Node ipl = q[2].substitute( vars.begin(), vars.end(), terms.begin(), terms.end() );
nq = NodeManager::currentNM()->mkNode( FORALL, bvl, body, ipl );
}else{
nq = NodeManager::currentNM()->mkNode( FORALL, bvl, body );
}
Trace("lte-partial-inst") << " - quantified conjunct : " << nq << std::endl;
LtePartialInstAttribute ltpia;
nq.setAttribute(ltpia,true);
conj.push_back( nq );
}
}else{
Assert( pindex<q[2][0].getNumChildren() );
Node pat = q[2][0][pindex];
Assert( pat.getNumChildren()==0 || paindex<=pat.getNumChildren() );
if( pat.getKind()==APPLY_UF ){
Assert( paindex<=pat.getNumChildren() );
if( paindex==pat.getNumChildren() ){
getPartialInstantiations( conj, q, bvl, vars, terms, types, NULL, pindex+1, 0, iindex );
}else{
if( !curr ){
Assert( paindex==0 );
//start traversing term index for the operator
curr = d_quantEngine->getTermDatabase()->getTermArgTrie( pat.getOperator() );
}
for( std::map< TNode, TermArgTrie >::iterator it = curr->d_data.begin(); it != curr->d_data.end(); ++it ){
terms[d_pat_var_order[q][iindex]] = it->first;
getPartialInstantiations( conj, q, bvl, vars, terms, types, &it->second, pindex, paindex+1, iindex+1 );
}
}
}else{
std::map< TypeNode, std::vector< Node > >::iterator it = d_reps.find( types[iindex] );
if( it!=d_reps.end() ){
Trace("lte-partial-inst-debug") << it->second.size() << " reps of type " << types[iindex] << std::endl;
for( unsigned i=0; i<it->second.size(); i++ ){
terms[d_pat_var_order[q][iindex]] = it->second[i];
getPartialInstantiations( conj, q, bvl, vars, terms, types, NULL, pindex+1, 0, iindex+1 );
}
}else{
Trace("lte-partial-inst-debug") << "No reps found of type " << types[iindex] << std::endl;
}
}
}
}
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