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/********************* */
/*! \file quant_epr.cpp
** \verbatim
** Top contributors (to current version):
** Andrew Reynolds, Morgan Deters, 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 quantifier EPR.
**/
#include "theory/quantifiers/quant_epr.h"
#include "theory/quantifiers/quant_util.h"
using namespace CVC4::kind;
namespace CVC4 {
namespace theory {
namespace quantifiers {
void QuantEPR::registerNode(Node n,
std::map<int, std::map<Node, bool> >& visited,
bool beneathQuant,
bool hasPol,
bool pol)
{
int vindex = hasPol ? (pol ? 1 : -1) : 0;
if (visited[vindex].find(n) == visited[vindex].end())
{
visited[vindex][n] = true;
Trace("quant-epr-debug") << "QuantEPR::registerNode " << n << std::endl;
if (n.getKind() == FORALL)
{
if (beneathQuant || !hasPol || !pol)
{
for (unsigned i = 0; i < n[0].getNumChildren(); i++)
{
TypeNode tn = n[0][i].getType();
if (d_non_epr.find(tn) == d_non_epr.end())
{
Trace("quant-epr") << "Sort " << tn
<< " is non-EPR because of nested or possible "
"existential quantification."
<< std::endl;
d_non_epr[tn] = true;
}
}
}
else
{
beneathQuant = true;
}
}
TypeNode tn = n.getType();
if (n.getNumChildren() > 0)
{
if (tn.isSort())
{
if (d_non_epr.find(tn) == d_non_epr.end())
{
Trace("quant-epr") << "Sort " << tn << " is non-EPR because of " << n
<< std::endl;
d_non_epr[tn] = true;
}
}
for (unsigned i = 0; i < n.getNumChildren(); i++)
{
bool newHasPol;
bool newPol;
QuantPhaseReq::getPolarity(n, i, hasPol, pol, newHasPol, newPol);
registerNode(n[i], visited, beneathQuant, newHasPol, newPol);
}
}
else if (tn.isSort())
{
if (n.getKind() == BOUND_VARIABLE)
{
if (d_consts.find(tn) == d_consts.end())
{
// mark that at least one constant must occur
d_consts[tn].clear();
}
}
else if (std::find(d_consts[tn].begin(), d_consts[tn].end(), n)
== d_consts[tn].end())
{
d_consts[tn].push_back(n);
Trace("quant-epr") << "...constant of type " << tn << " : " << n
<< std::endl;
}
}
}
}
void QuantEPR::registerAssertion(Node assertion)
{
std::map<int, std::map<Node, bool> > visited;
registerNode(assertion, visited, false, true, true);
}
void QuantEPR::finishInit()
{
Trace("quant-epr-debug") << "QuantEPR::finishInit" << std::endl;
for (std::map<TypeNode, std::vector<Node> >::iterator it = d_consts.begin();
it != d_consts.end();
++it)
{
Assert(d_epr_axiom.find(it->first) == d_epr_axiom.end());
Trace("quant-epr-debug") << "process " << it->first << std::endl;
if (d_non_epr.find(it->first) != d_non_epr.end())
{
Trace("quant-epr-debug") << "...non-epr" << std::endl;
it->second.clear();
}
else
{
Trace("quant-epr-debug") << "...epr, #consts = " << it->second.size()
<< std::endl;
if (it->second.empty())
{
it->second.push_back(NodeManager::currentNM()->mkSkolem(
"e", it->first, "EPR base constant"));
}
if (Trace.isOn("quant-epr"))
{
Trace("quant-epr") << "Type " << it->first
<< " is EPR, with constants : " << std::endl;
for (unsigned i = 0; i < it->second.size(); i++)
{
Trace("quant-epr") << " " << it->second[i] << std::endl;
}
}
}
}
}
bool QuantEPR::isEPRConstant(TypeNode tn, Node k)
{
return std::find(d_consts[tn].begin(), d_consts[tn].end(), k)
!= d_consts[tn].end();
}
void QuantEPR::addEPRConstant(TypeNode tn, Node k)
{
Assert(isEPR(tn));
Assert(d_epr_axiom.find(tn) == d_epr_axiom.end());
if (!isEPRConstant(tn, k))
{
d_consts[tn].push_back(k);
}
}
Node QuantEPR::mkEPRAxiom(TypeNode tn)
{
Assert(isEPR(tn));
std::map<TypeNode, Node>::iterator ita = d_epr_axiom.find(tn);
if (ita == d_epr_axiom.end())
{
std::vector<Node> disj;
Node x = NodeManager::currentNM()->mkBoundVar(tn);
for (unsigned i = 0; i < d_consts[tn].size(); i++)
{
disj.push_back(
NodeManager::currentNM()->mkNode(EQUAL, x, d_consts[tn][i]));
}
Assert(!disj.empty());
d_epr_axiom[tn] = NodeManager::currentNM()->mkNode(
FORALL,
NodeManager::currentNM()->mkNode(BOUND_VAR_LIST, x),
disj.size() == 1 ? disj[0]
: NodeManager::currentNM()->mkNode(OR, disj));
return d_epr_axiom[tn];
}
else
{
return ita->second;
}
}
} /* CVC4::theory::quantifiers namespace */
} /* CVC4::theory namespace */
} /* CVC4 namespace */
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