public void Empty() { NFA nfa = NFA.Empty(); DFA dfa = nfa.ToDfa(); Assert.IsTrue(dfa.IsMatch("")); Assert.IsFalse(dfa.IsMatch("a")); Assert.IsFalse(dfa.IsMatch("b")); Assert.IsFalse(dfa.IsMatch("ab")); Assert.IsFalse(dfa.IsMatch("aaaa")); Assert.IsFalse(dfa.IsMatch("bbb")); }