This chapter includes contents: RE, Recursive definition of RE, defining languages by RE, { x}*, { x}+, {a+b}*, language of strings having exactly one aa, Language of strings of even length, language of strings of odd length, RE defines unique language (as Remark), language of strings having at least one a, language of strings havgin at least one a and one b, Language of strings starting with aa and ending in bb, Language of strings starting with and ending in different letters. | Lecture note Theory of automata - Lecture 3
