examples/simple_vc_cxx.cpp

   1 /*********************                                                        */
   2 /*! \file simple_vc_cxx.cpp
   3  ** \verbatim
   4  ** Original author: mdeters
   5  ** Major contributors: none
   6  ** Minor contributors (to current version): dejan
   7  ** This file is part of the CVC4 prototype.
   8  ** Copyright (c) 2009-2012  New York University and The University of Iowa
   9  ** See the file COPYING in the top-level source directory for licensing
  10  ** information.\endverbatim
  11  **
  12  ** \brief A simple demonstration of the C++ interface
  13  **
  14  ** A simple demonstration of the C++ interface.  Compare to the Java
  15  ** interface in SimpleVC.java; they are virtually line-by-line
  16  ** identical.
  17  **/
  18
  19 #include <iostream>
  20
  21 //#include <cvc4/cvc4.h> // use this after CVC4 is properly installed
  22 #include "smt/smt_engine.h"
  23
  24 using namespace std;
  25 using namespace CVC4;
  26
  27 int main() {
  28   ExprManager em;
  29   SmtEngine smt(&em);
  30
  31   // Prove that for integers x and y:
  32   //   x > 0 AND y > 0  =>  2x + y >= 3
  33
  34   Type integer = em.integerType();
  35
  36   Expr x = em.mkVar("x", integer);
  37   Expr y = em.mkVar("y", integer);
  38   Expr zero = em.mkConst(Rational(0));
  39
  40   Expr x_positive = em.mkExpr(kind::GT, x, zero);
  41   Expr y_positive = em.mkExpr(kind::GT, y, zero);
  42
  43   Expr two = em.mkConst(Rational(2));
  44   Expr twox = em.mkExpr(kind::MULT, two, x);
  45   Expr twox_plus_y = em.mkExpr(kind::PLUS, twox, y);
  46
  47   Expr three = em.mkConst(Rational(3));
  48   Expr twox_plus_y_geq_3 = em.mkExpr(kind::GEQ, twox_plus_y, three);
  49
  50   Expr formula =
  51     em.mkExpr(kind::AND, x_positive, y_positive).
  52     impExpr(twox_plus_y_geq_3);
  53
  54   cout << "Checking validity of formula " << formula << " with CVC4." << endl;
  55   cout << "CVC4 should report VALID." << endl;
  56   cout << "Result from CVC4 is: " << smt.query(formula) << endl;
  57
  58   return 0;
  59 }