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+/*********************                                                        */
+/*! \file sygus-inv.cpp
+ ** \verbatim
+ ** Top contributors (to current version):
+ **   Abdalrhman Mohamed, Andrew Reynolds
+ ** This file is part of the CVC4 project.
+ ** Copyright (c) 2009-2019 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 Sygus API.
+ **
+ ** A simple demonstration of how to use the Sygus API to synthesize a simple
+ ** invariant. Here is the same problem written in Sygus V2 format:
+ **
+ ** (set-logic LIA)
+ **
+ ** (synth-inv inv-f ((x Int)))
+ **
+ ** (define-fun pre-f ((x Int)) Bool
+ **   (= x 0))
+ ** (define-fun trans-f ((x Int) (xp Int)) Bool
+ **   (ite (< x 10) (= xp (+ x 1)) (= xp x)))
+ ** (define-fun post-f ((x Int)) Bool
+ **   (<= x 10))
+ **
+ ** (inv-constraint inv-f pre-f trans-f post-f)
+ **
+ ** (check-synth)
+ **
+ ** The printed output to this example should be equivalent to:
+ ** (define-fun inv-f ((x Int)) Bool (not (>= x 11)))
+ **/
+
+#include <cvc4/api/cvc4cpp.h>
+
+#include <iostream>
+
+using namespace CVC4::api;
+
+int main()
+{
+  Solver slv;
+
+  // required options
+  slv.setOption("lang", "sygus2");
+  slv.setOption("incremental", "false");
+
+  // set the logic
+  slv.setLogic("LIA");
+
+  Sort integer = slv.getIntegerSort();
+  Sort boolean = slv.getBooleanSort();
+
+  Term zero = slv.mkReal(0);
+  Term one = slv.mkReal(1);
+  Term ten = slv.mkReal(10);
+
+  // declare input variables for functions
+  Term x = slv.mkVar(integer, "x");
+  Term xp = slv.mkVar(integer, "xp");
+
+  // (ite (< x 10) (= xp (+ x 1)) (= xp x))
+  Term ite = slv.mkTerm(ITE,
+                        slv.mkTerm(LT, x, ten),
+                        slv.mkTerm(EQUAL, xp, slv.mkTerm(PLUS, x, one)),
+                        slv.mkTerm(EQUAL, xp, x));
+
+  // define the pre-conditions, transition relations, and post-conditions
+  Term pre_f = slv.defineFun("pre-f", {x}, boolean, slv.mkTerm(EQUAL, x, zero));
+  Term trans_f = slv.defineFun("trans-f", {x, xp}, boolean, ite);
+  Term post_f = slv.defineFun("post-f", {x}, boolean, slv.mkTerm(LEQ, x, ten));
+
+  // declare the invariant-to-synthesize.
+  Term inv_f = slv.synthInv("inv-f", {x});
+
+  slv.addSygusInvConstraint(inv_f, pre_f, trans_f, post_f);
+
+  // print solutions if available
+  if (slv.checkSynth().isUnsat())
+  {
+    // Output should be equivalent to:
+    // (define-fun inv-f ((x Int)) Bool (not (>= x 11)))
+    slv.printSynthSolution(std::cout);
+  }
+
+  return 0;
+}