examples/SimpleVCCompat.java

   1 /*********************                                                        */
   2 /*! \file SimpleVCCompat.java
   3  ** \verbatim
   4  ** Original author: Morgan Deters
   5  ** Major contributors: none
   6  ** Minor contributors (to current version): none
   7  ** This file is part of the CVC4 project.
   8  ** Copyright (c) 2009-2013  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 Java compatibility interface
  13  ** (quite similar to the old CVC3 Java interface)
  14  **
  15  ** A simple demonstration of the Java compatibility interface
  16  ** (quite similar to the old CVC3 Java interface).
  17  **
  18  ** To run the resulting class file, you need to do something like the
  19  ** following:
  20  **
  21  **   java \
  22  **     -classpath path/to/CVC4compat.jar \
  23  **     -Djava.library.path=/dir/containing/libcvc4bindings_java_compat.so \
  24  **     SimpleVCCompat
  25  **
  26  ** For example, if you are building CVC4 without specifying your own
  27  ** build directory, the build process puts everything in builds/, and
  28  ** you can run this example (after building it with "make") like this:
  29  **
  30  **   java \
  31  **     -classpath builds/examples:builds/src/bindings/compat/java/CVC4compat.jar \
  32  **     -Djava.library.path=builds/src/bindings/compat/java/.libs \
  33  **     SimpleVCCompat
  34  **/
  35
  36 import cvc3.*;
  37
  38 public class SimpleVCCompat {
  39   public static void main(String[] args) {
  40     ValidityChecker vc = ValidityChecker.create();
  41
  42     // Prove that for integers x and y:
  43     //   x > 0 AND y > 0  =>  2x + y >= 3
  44
  45     Type integer = vc.intType();
  46
  47     Expr x = vc.varExpr("x", integer);
  48     Expr y = vc.varExpr("y", integer);
  49     Expr zero = vc.ratExpr(0);
  50
  51     Expr x_positive = vc.gtExpr(x, zero);
  52     Expr y_positive = vc.gtExpr(y, zero);
  53
  54     Expr two = vc.ratExpr(2);
  55     Expr twox = vc.multExpr(two, x);
  56     Expr twox_plus_y = vc.plusExpr(twox, y);
  57
  58     Expr three = vc.ratExpr(3);
  59     Expr twox_plus_y_geq_3 = vc.geExpr(twox_plus_y, three);
  60
  61     Expr formula = vc.impliesExpr(vc.andExpr(x_positive, y_positive),
  62                                   twox_plus_y_geq_3);
  63
  64     System.out.println("Checking validity of formula " + formula + " with CVC4.");
  65     System.out.println("CVC4 should report VALID.");
  66     System.out.println("Result from CVC4 is: " + vc.query(formula));
  67   }
  68 }