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/********************* */
/*! \file simple_vc_cxx.cpp
** \verbatim
** Top contributors (to current version):
** Morgan Deters, Dejan Jovanovic, Aina Niemetz
** This file is part of the CVC4 project.
** Copyright (c) 2009-2020 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 A simple demonstration of the C++ interface
**
** A simple demonstration of the C++ interface. Compare to the Java
** interface in SimpleVC.java; they are virtually line-by-line
** identical.
**/
#include <iostream>
#include <cvc4/cvc4.h>
using namespace std;
using namespace CVC4;
int main() {
ExprManager em;
SmtEngine smt(&em);
// Prove that for integers x and y:
// x > 0 AND y > 0 => 2x + y >= 3
Type integer = em.integerType();
Expr x = em.mkVar("x", integer);
Expr y = em.mkVar("y", integer);
Expr zero = em.mkConst(Rational(0));
Expr x_positive = em.mkExpr(kind::GT, x, zero);
Expr y_positive = em.mkExpr(kind::GT, y, zero);
Expr two = em.mkConst(Rational(2));
Expr twox = em.mkExpr(kind::MULT, two, x);
Expr twox_plus_y = em.mkExpr(kind::PLUS, twox, y);
Expr three = em.mkConst(Rational(3));
Expr twox_plus_y_geq_3 = em.mkExpr(kind::GEQ, twox_plus_y, three);
Expr formula =
em.mkExpr(kind::AND, x_positive, y_positive).
impExpr(twox_plus_y_geq_3);
cout << "Checking entailment of formula " << formula << " with CVC4." << endl;
cout << "CVC4 should report ENTAILED." << endl;
cout << "Result from CVC4 is: " << smt.checkEntailed(formula) << endl;
return 0;
}
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