public void Plus()
{
NFA nfa = NFA.Plus(NFA.Sequence(NFA.Char('a'), NFA.Char('b')));
DFA dfa = nfa.ToDfa();
Assert.IsFalse(dfa.IsMatch(""));
Assert.IsFalse(dfa.IsMatch("a"));
Assert.IsFalse(dfa.IsMatch("b"));
Assert.IsFalse(dfa.IsMatch("aa"));
Assert.IsFalse(dfa.IsMatch("bb"));
Assert.IsFalse(dfa.IsMatch("ba"));
Assert.IsFalse(dfa.IsMatch("cc"));
Assert.IsFalse(dfa.IsMatch("aaa"));
Assert.IsFalse(dfa.IsMatch("aba"));
Assert.IsFalse(dfa.IsMatch("abb"));
Assert.IsTrue(dfa.IsMatch("ab"));
Assert.IsTrue(dfa.IsMatch("abab"));
Assert.IsTrue(dfa.IsMatch("ababab"));
}