public void MSOLast()
        {
            var solver = new CharSetSolver(BitWidth.BV64);  //new solver using ASCII encoding

            List<char> alph = new List<char> { 'a', 'b' };
            HashSet<char> al = new HashSet<char>(alph);

            //ex x. first(x)
            MSOFormula formula = new MSOExistsFO("x", new MSOLast("x"));

            Assert.IsTrue(formula.CheckUseOfVars());

            var dfa = formula.getDFA(al, solver);

            var test = solver.Convert(@"^(a|b)+$");

            Assert.IsTrue(dfa.IsEquivalentWith(test, solver));

            string file = "../../../MSOZ3Test/DotFiles/exlast";

            solver.SaveAsDot(dfa, "aut", file);   //extension .dot  is added automatically when missing
        }
        public void MSO2a2b()
        {
            var solver = new CharSetSolver(BitWidth.BV64);  //new solver using ASCII encoding

            List<char> alph = new List<char> { 'a', 'b' };
            HashSet<char> al = new HashSet<char>(alph);

            MSOFormula formula1 = new MSOExistsFO("x1",
                                    new MSOExistsFO("x2",
                                        new MSOAnd(
                                            new MSOAnd(
                                                new MSOLabel("x1", 'a'),
                                                new MSOLabel("x2", 'a')),
                                            new MSONot(
                                                new MSOEqual("x1", "x2")))));
            MSOFormula formula2 = new MSOExistsFO("x1",
                                    new MSOExistsFO("x2",
                                        new MSOAnd(
                                            new MSOAnd(
                                                new MSOLabel("x1", 'b'),
                                                new MSOLabel("x2", 'b')),
                                            new MSONot(
                                                new MSOEqual("x1", "x2")))));

            MSOFormula formula = new MSOAnd(formula1, formula2);


            Assert.IsTrue(formula.CheckUseOfVars());

            var WS1S = formula.ToWS1S(solver);
            var dfa = WS1S.getDFA(al, solver);
            var timer = new Stopwatch();
            var tt = 100;
            var acc = 0L;
            for (int k = 0; k < tt; k++)
            {
                timer.Reset();
                timer.Start();
                dfa = WS1S.getDFA(al, solver);
                timer.Stop();
                acc += timer.ElapsedMilliseconds;
            }
            Console.WriteLine("time: " + acc / tt + " ms");

            //var test = solver.Convert(@"^(a|b)$");

            //Assert.IsTrue(dfa.IsEquivalentWith(test, solver));

            string file = "../../../MSOZ3Test/DotFiles/a2b2";
            solver.SaveAsDot(dfa, "aut", file);   //extension .dot  is added automatically when missing
        }