examples/SimpleVCCompat.java

   1 /*********************                                                        */
   2 /*! \file SimpleVCCompat.java
   3  ** \verbatim
   4  ** Original author: mdeters
   5  ** Major contributors: none
   6  ** Minor contributors (to current version): none
   7  ** This file is part of the CVC4 prototype.
   8  ** Copyright (c) 2009, 2010, 2011  The Analysis of Computer Systems Group (ACSys)
   9  ** Courant Institute of Mathematical Sciences
  10  ** New York University
  11  ** See the file COPYING in the top-level source directory for licensing
  12  ** information.\endverbatim
  13  **
  14  ** \brief A simple demonstration of the Java compatibility interface
  15  ** (quite similar to the old CVC3 Java interface)
  16  **
  17  ** A simple demonstration of the Java compatibility interface
  18  ** (quite similar to the old CVC3 Java interface).
  19  **
  20  ** To run the resulting class file, you need to do something like the
  21  ** following:
  22  **
  23  **   java \
  24  **     -classpath path/to/CVC4compat.jar \
  25  **     -Djava.library.path=/dir/containing/libcvc4bindings_java_compat.so \
  26  **     SimpleVCCompat
  27  **
  28  ** For example, if you are building CVC4 without specifying your own
  29  ** build directory, the build process puts everything in builds/, and
  30  ** you can run this example (after building it with "make") like this:
  31  **
  32  **   java \
  33  **     -classpath builds/examples:builds/src/bindings/compat/java/CVC4compat.jar \
  34  **     -Djava.library.path=builds/src/bindings/compat/java/.libs \
  35  **     SimpleVCCompat
  36  **/
  37
  38 import cvc3.*;
  39
  40 public class SimpleVCCompat {
  41   public static void main(String[] args) {
  42     //System.loadLibrary("cvc4bindings_java_compat");
  43
  44     ValidityChecker vc = ValidityChecker.create();
  45
  46     // Prove that for integers x and y:
  47     //   x > 0 AND y > 0  =>  2x + y >= 3
  48
  49     Type integer = vc.intType();
  50
  51     Expr x = vc.varExpr("x", integer);
  52     Expr y = vc.varExpr("y", integer);
  53     Expr zero = vc.ratExpr(0);
  54
  55     Expr x_positive = vc.gtExpr(x, zero);
  56     Expr y_positive = vc.gtExpr(y, zero);
  57
  58     Expr two = vc.ratExpr(2);
  59     Expr twox = vc.multExpr(two, x);
  60     Expr twox_plus_y = vc.plusExpr(twox, y);
  61
  62     Expr three = vc.ratExpr(3);
  63     Expr twox_plus_y_geq_3 = vc.geExpr(twox_plus_y, three);
  64
  65     Expr formula = vc.impliesExpr(vc.andExpr(x_positive, y_positive),
  66                                   twox_plus_y_geq_3);
  67
  68     System.out.println("Checking validity of formula " + formula + " with CVC4.");
  69     System.out.println("CVC4 should report VALID.");
  70     System.out.println("Result from CVC4 is: " + vc.query(formula));
  71   }
  72 }