2. Dept. of Computer Science & IT, FUUAST Automata Theory 2 Automata Theory III Properties of Regular Languages 1.Closure 2.Union 3.Concatenation 4.Complement(Negation) 5.Kleene Star 6.Reverse 7.Intersection 8.Difference 9.Homomorphism

4. Dept. of Computer Science & IT, FUUAST Automata Theory 4 Automata Theory IV Pumping Lemma Let L be a regular language. Then there exists a constant n (which depends on L) such that for every string w in L such that |w|  n, we can break w into three strings, w= xyz, such that: 1.y  . 2.|xy|  n. 3.For all k  0, the string xy k z is also in L.

5. Dept. of Computer Science & IT, FUUAST Automata Theory 5 Automata Theory IV Pumping Lemma