RS#1 - The class of regular languages FA Some real-world examples DFA Formal Description State diagram Languages NFA Conversion to DFA (power set construction) Conversion to RE (GNFA construction and then "rips") RE What makes a RE (Don't forget about NULL) Conversion to NFA For DFA, NFA and RE: Creating from a language description Discerning language from each Converting from one to another (as above) Prove a language is a regular language (by doing one of these) Understanding finite memory - - - state memory Some languages are not regular: pumping lemma for regular languages -using to prove a language is not regular -understanding the pigeonhole and loop idea closure -reverse, intersection, Kleene operators -can help to prove a language is not regular