UNIT II SYLLABUS•REGULAR EXPRESSIONS AND REGULAR SETS : Regular Expressions and Identities for Regular Expressions, Finite Automata and Regular Expressions: Transition System Containing null moves, NDFA with null moves and Regular Expressions, Conversion of Non-deterministic Systems to Deterministic Systems, Algebraic Methods using Arden's Theorem, Construction of Finite Automata Equivalent to a Regular Expression, Equivalence of Two Finite Automata and Two Regular Expressions, Closure Properties of Regular Sets, Pumping Lemma for Regular Sets and its Application, Equivalence between regular languages: Construction of Finite Automata Equivalent to a Regular Expression, Properties of Regular Languages, Non-deterministic Finite Automata with Null Moves and Regular Expressions, Myhill-Nerode Theorem
REGULAR EXPRESSIONS•The language accepted by finite automata can be easily described by simple expressions called Regular Expressions. It is the most effective way to represent any language.•The languages accepted by some regular expression are referred to as Regular languages•A regular expression can also be described as a sequence of pattern that defines a string.•Regular expressions are used to match character combinations in strings. String searching algorithm used this pattern to find the operations on a string..
REGULAR EXPRESSIONS•A Regular Expressioncan be recursively defined