This book arose from our lectures on Artificial Intelligence at the Uttaranchal Institute of Technology, Dehradun and later at the Dehradun Institute of Technology, Dehradun. We started writing a new text out of dissatisfaction with the literature available at the time. Most books on Artificial Intelligence seemed to be chaotic collections of models and there was no clear unifying theoretical thread connecting them. The results of my efforts are published in this book. We tried in this book to put the accent on a systematic development of Artificial Intelligence theory and to stimulate the intuition of the reader by making use of many figures. Intuitive understanding fosters a more immediate grasp of the objects one studies, which stresses the concrete meaning of their relations. Since then some new books have appeared, which are more systematic and comprehensive than those previously available, but We think that there is still much room for improvement. The book has been written for undergraduates, and the only mathematical tools needed are those which are learned during the years at Institute.