In today's world of intense information dissemination and globalisation, the need of the hour is to bring out a well-structured and authentic textbook, especially in the field of computer science and technology. Our humble effort in this regard is to make a sincere value addition through this textbook.

This book is the culmination of our fascination for the subject of computation and its applications. It has been designed for students of computer science at the postgraduate level and is logically conceived, self-contained, well-organised and user-friendly.

The book contains an in-depth coverage of all the topics related to the theory of computation as mentioned in the syllabuses of B.E., M.C.A. and M.Sc. (Computer Science) of various universities. Sufficient amount of theoretical inputs supported by a number of illustrations are included for those who take deep interest in the subject.

The book includes 15 chapters, segregated into three sections. Part one ‘Fundamentals of Computation’, contains chapters 1 to 3. Chapter 1 is introductory in nature and gives a broad picture of the subject. Chapters 2 and 3 discuss Formal Language Theory and Regular Expressions and Languages. Part two ‘Models and Principles of Computation’, comprises chapters 4 to 7, and discusses topics like Finite State Machine, Equivalent Automata, Optimisation/Minimisation of DFA, Finite Automata and Regular Expressions, Transducers et cetera in a systematic way. Finally, part three ‘Advanced Models and Principles of Computation’ includes chapter 9 to 15, and addresses issues of Context- Free Grammar and Context-Free Languages, Simplification of Context-Free Grammar, Pushdown Automata, Pumping Lemma, Turing Machine, TM Extensions and Languages and Formal Languages/Grammar Hierarchy .