PPT-Chapter 3 REGULAR LANGUAGES AND REGULAR GRAMMARS

Chapter 3 REGULAR LANGUAGES AND REGULAR GRAMMARS Learning Objectives At the conclusion of the chapter the student will be able to Identify the language associated with a regular expression Find a regular expression to describe a given language. 1. . Theory of Computation Peer Instruction Lecture Slides by . Dr. Cynthia Lee, UCSD.  are licensed under a . Creative Commons Attribution-. NonCommercial. -. ShareAlike. 3.0 . Unported. License. Definitions. Equivalence to Finite Automata. 2. RE. ’. s: Introduction. Regular expressions. describe languages by an algebra.. They describe exactly the regular languages.. If E is a regular expression, then L(E) is the language it defines.. Formal definition of a regular expression.. Languages associated with regular expressions.. Introduction regular grammars. . Regular language and homomorphism. . The Chomsky Hierarchy . Regular Expression. . 2. . Regular Languages. 3. . Regular Languages. Context-Free Languages. 4. Context-Free Languages. Pushdown. Automata. Context-Free. Grammars. stack. automaton. 5. Context-Free Grammars. . 6. Grammars. Sipser. 1.1 (pages 44 – 47). Building languages. If L is a language, then its . complement. is. . L’ = {. w. | . w. ∉ L}. Let . A = {. w. | . w. . is a string of . 0. s and . 1. s containing an odd number of 1s. Reading: Chapter 4. 2. Topics. How to prove whether a given language is regular or not?. Closure properties of regular languages. Minimization of DFAs. 3. Some languages are . not . regular. When is a language is regular? . Regular Languages. The regular languages are the languages that DFA accept.. Since DFA are equivalent with NFA. ε. , in order to show that L is regular it suffices to construct an NFA. ε. . that recognizes L.. Regular Languages. Regular languages are the languages which are accepted by a Finite Automaton.. Not all languages are regular. Non-Regular Languages. L. 0. = {. a. k. b. k. : k≤0} = . {ε}. is a regular language. General grammars. Context Sensitive grammars. Context Free grammars. Linear . grammars. Grammar types. There are 4 types of grammars according to the types of rules:. Each type recognizes a set of languages. . Sandiway Fong. From last time. Ungraded Homework . 9. apply the set-of-states construction technique to the two machines on the . ε. -. transition slide (repeated below). self-check your answer: . verify in each case that the machine produced is deterministic and accurately simulates its . some languages are not regular!. Sipser. pages 77 - 82. Are all Languages Regular. We have seen many ways. to specify Regular languages. Are all languages Regular languages?. The answer is No, . H. Learning . Objectives. At the conclusion of the chapter, the student will be able to:. State the closure properties applicable to regular languages. Prove that regular languages are closed under union, concatenation, star-closure, complementation, and intersection. AntConc concordance tool. University of Bucharest. Digital Humanities Master. February 2020. Anca Dinu. Regular expressions. In corpus linguistics. much of what we want to do . with a tool. is pattern-matching over texts/corpora. 2. Regular Expressions vs. Finite Automata. Offers a declarative way to express the pattern of any string we want to accept . E.g., . 01*+ 10*. Automata => more machine-like . < input: string , output: [accept/reject] >.