The main contents of this chapter include all of the following: Intersection of two regular languages is regular, examples, non regular language, example. | Lecture # 1 Theory Of Automata By Dr. MM Alam 1 Text and Reference Material Introduction to Computer Theory, by Daniel I. Cohen, John Wiley and Sons, Inc., 1991, Second Edition (as a Text Book) Introduction to Languages and Theory of Computation, by J. C. Martin, McGraw Hill Book Co., 1997, Second Edition (for Additional Reading) What does Theory of automata mean? The word “Theory” means that this subject is a more mathematical subject and less practical. It is not like your other courses such as programming. However, this subject is the foundation for many other practical subjects. Automata is the plural of the word Automaton which means “self-acting” In general, this subject focuses on the theoretical aspects of computer science. Theory of Automa Applications This subject plays a major role in: Theory of Computation Compiler Construction Parsing Formal Verification Defining computer languages Types of languages There are two types of languages Formal Languages are used as a basis . | Lecture # 1 Theory Of Automata By Dr. MM Alam 1 Text and Reference Material Introduction to Computer Theory, by Daniel I. Cohen, John Wiley and Sons, Inc., 1991, Second Edition (as a Text Book) Introduction to Languages and Theory of Computation, by J. C. Martin, McGraw Hill Book Co., 1997, Second Edition (for Additional Reading) What does Theory of automata mean? The word “Theory” means that this subject is a more mathematical subject and less practical. It is not like your other courses such as programming. However, this subject is the foundation for many other practical subjects. Automata is the plural of the word Automaton which means “self-acting” In general, this subject focuses on the theoretical aspects of computer science. Theory of Automa Applications This subject plays a major role in: Theory of Computation Compiler Construction Parsing Formal Verification Defining computer languages Types of languages There are two types of languages Formal Languages are used as a basis for defining computer languages A predefined set of symbols and string Formal language theory studies purely syntactical aspects of a language (., word abcd) Informal Languages such as English has many different versions. Basic Element of a Formal Language – Alphabets Definition: A finite non-empty set of symbols (letters), is called an alphabet. It is denoted by Greek letter sigma Σ. Example: Σ={1,2,3} Σ={0,1} //Binary digits Σ={i,j,k} Example Computer Languages C Language Java Language C++ Java Visual C++ What are Strings A String is formed by combining various symbols from an alphabet. Example: If Σ= {1,0} then 0, 1, 110011, Similarly, If Σ= {a,b} then a, b, abbbbbb, aaaabbbbb, What is an EMPTY or NULL String A string with no symbol is denoted by (Small Greek letter Lambda) λ or (Capital Greek letter Lambda) Λ. It is called an empty string or null string. We will prefer Λ in this course. Please don’t confuse it with logical operator ‘and’. One important thing to note is .