This edition is a revision of 2002 edition of the book. Considerable attention has been given to improve the first edition. As far as possible efforts were made to keep the book free from typographic and other errors. Most of the changes were made at the suggestions of the individuals who have used the first edition of the book and who were kind enough to send their comments. Enhancements to the material devoted to mathematical logic methods of proof, combinations and graph theory are designed to help the readers master the subject.
I am thankful to the chief editor and the editors of New Age International (P) Limited, Publishers for the interest and cooperation during the production of the second edition of the book.
The author would like to express his appreciation to Sri Saumya Gupta, Managing Director, New Age International (P) Limited, for his encouragement.
Any suggestions for future improvements of this book will be gratefully received