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/********************* -*- C++ -*- */
/** smt_engine.cpp
** Original author: mdeters
** Major contributors: dejan
** Minor contributors (to current version): none
** This file is part of the CVC4 prototype.
** Copyright (c) 2009 The Analysis of Computer Systems Group (ACSys)
** Courant Institute of Mathematical Sciences
** New York University
** See the file COPYING in the top-level source directory for licensing
** information.
**
**/
#include "smt/smt_engine.h"
#include "util/exception.h"
#include "util/command.h"
#include "util/output.h"
#include "expr/node_builder.h"
namespace CVC4 {
SmtEngine::SmtEngine(ExprManager* em, Options* opts) throw() :
d_assertions(),
d_public_em(em),
d_nm(em->getNodeManager()),
d_opts(opts),
d_de(),
d_te(),
d_prop(d_de, d_te) {
}
SmtEngine::~SmtEngine() {
}
void SmtEngine::doCommand(Command* c) {
NodeManagerScope nms(d_nm);
c->invoke(this);
}
void SmtEngine::orHelper(Node::iterator p, Node::iterator end, NodeBuilder<>& result) {
if(p == end) {
return;
} else if((*p).getKind() == AND) {
NodeBuilder<> resultPrefix = result;
result = NodeBuilder<>(AND);
for(Node::iterator i = (*p).begin(); i != (*p).end(); ++i) {
NodeBuilder<> r = resultPrefix;
r << preprocess(*i);
Node::iterator p2 = p;
orHelper(++p2, end, r);
result << r;
}
} else {
result << preprocess(*p);
}
}
Node SmtEngine::preprocess(const Node& e) {
if(e.getKind() == NOT) {
// short-circuit trivial NOTs
if(e[0].getKind() == TRUE) {
return d_nm->mkNode(FALSE);
} else if(e[0].getKind() == FALSE) {
return d_nm->mkNode(TRUE);
} else if(e[0].getKind() == NOT) {
return preprocess(e[0][0]);
} else {
Node f = preprocess(e[0]);
// push NOTs inside of ANDs and ORs
if(f.getKind() == AND) {
NodeBuilder<> n(OR);
for(Node::iterator i = f.begin(); i != f.end(); ++i) {
if((*i).getKind() == NOT) {
n << (*i)[0];
} else {
n << d_nm->mkNode(NOT, *i);
}
}
return n;
}
if(f.getKind() == OR) {
NodeBuilder<> n(AND);
for(Node::iterator i = f.begin(); i != f.end(); ++i) {
if((*i).getKind() == NOT) {
n << (*i)[0];
} else {
n << d_nm->mkNode(NOT, *i);
}
}
return n;
}
}
} else if(e.getKind() == AND) {
NodeBuilder<> n(AND);
// flatten ANDs
for(Node::iterator i = e.begin(); i != e.end(); ++i) {
Node f = preprocess(*i);
if((*i).getKind() == AND) {
for(Node::iterator j = f.begin(); j != f.end(); ++j) {
n << *j;
}
} else {
n << *i;
}
}
return n;
} else if(e.getKind() == OR) {
NodeBuilder<> n(OR);
// flatten ORs
for(Node::iterator i = e.begin(); i != e.end(); ++i) {
if((*i).getKind() == OR) {
Node f = preprocess(*i);
for(Node::iterator j = f.begin(); j != f.end(); ++j) {
n << *j;
}
}
}
Node nod = n;
NodeBuilder<> m(OR);
orHelper(nod.begin(), nod.end(), m);
return m;
}
return e;
}
Node SmtEngine::processAssertionList() {
if(d_assertions.size() == 1) {
return d_assertions[0];
}
NodeBuilder<> asserts(AND);
for(std::vector<Node>::iterator i = d_assertions.begin();
i != d_assertions.end();
++i) {
asserts << *i;
}
return asserts;
}
Result SmtEngine::check() {
Node asserts = processAssertionList();
d_prop.solve(asserts);
return Result(Result::VALIDITY_UNKNOWN);
}
Result SmtEngine::quickCheck() {
processAssertionList();
return Result(Result::VALIDITY_UNKNOWN);
}
void SmtEngine::addFormula(const Node& e) {
Debug("smt") << "push_back assertion " << e << std::endl;
d_assertions.push_back(e);
}
Result SmtEngine::checkSat(const BoolExpr& e) {
NodeManagerScope nms(d_nm);
Node node_e = preprocess(e.getNode());
addFormula(node_e);
return check();
}
Result SmtEngine::query(const BoolExpr& e) {
NodeManagerScope nms(d_nm);
Node node_e = preprocess(d_nm->mkNode(NOT, e.getNode()));
addFormula(node_e);
return check();
}
Result SmtEngine::assertFormula(const BoolExpr& e) {
NodeManagerScope nms(d_nm);
Node node_e = preprocess(e.getNode());
addFormula(node_e);
return quickCheck();
}
Expr SmtEngine::simplify(const Expr& e) {
Expr simplify(const Expr& e);
Unimplemented();
}
}/* CVC4 namespace */
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