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###################### ##
##! \file SimpleVC.py
### \verbatim
### Original author: mdeters
### Major contributors: none
### Minor contributors (to current version): none
### This file is part of the CVC4 prototype.
### Copyright (c) 2009, 2010, 2011 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.\endverbatim
###
### \brief A simple demonstration of the Python interface
###
### A simple demonstration of the Python interface. Compare to the
### C++ interface in simple_vc_cxx.cpp; they are quite similar.
###
### To run, use something like:
###
### PYTHONPATH=/dir/containing/CVC4.py:$PYTHONPATH \
### python \
### -Djava.library.path=/dir/containing/libcvc4bindings_python.so \
### SimpleVC
####
from ctypes import cdll
cdll.LoadLibrary('libcvc4.so')
cdll.LoadLibrary('libcvc4parser.so')
cdll.LoadLibrary('libcvc4bindings_python.so')
import CVC4
def main():
em = ExprManager()
smt = SmtEngine(em)
# Prove that for integers x and y:
# x > 0 AND y > 0 => 2x + y >= 3
integer = em.integerType()
x = em.mkVar("x", integer)
y = em.mkVar("y", integer)
zero = em.mkConst(Integer(0))
x_positive = em.mkExpr(kind.GT, x, zero)
y_positive = em.mkExpr(kind.GT, y, zero)
two = em.mkConst(Integer(2))
twox = em.mkExpr(kind.MULT, two, x)
twox_plus_y = em.mkExpr(kind.PLUS, twox, y)
three = em.mkConst(Integer(3))
twox_plus_y_geq_3 = em.mkExpr(kind.GEQ, twox_plus_y, three)
formula = BoolExpr(em.mkExpr(kind.AND, x_positive, y_positive)).impExpr(BoolExpr(twox_plus_y_geq_3))
print "Checking validity of formula " << formula << " with CVC4." << endl
print "CVC4 should report VALID." << endl
print "Result from CVC4 is: " << smt.query(formula) << endl
return 0
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