This book proposes a new approach to circuit simulation that is still in its infancy. The reason for publishing this work as a monograph at this time is to quickly distribute these ideas to the research community for further study. The book is based on a doctoral dissertation undertaken at MIT between 1982 and 1985. In 1982 the author joined a research group that was applying bounding techniques to simple VLSI timing analysis models. The conviction that bounding analysis could also be successfully applied to sophisticated digital MOS circuit models led to the research presented here. Acknowledgments 'me author would like to acknowledge many helpful discussions and much support from his research group at MIT, including Lance Glasser, John Wyatt, Jr. , and Paul Penfield, Jr. Many others have also contributed to this work in some way, including Albert Ruchli, Mark Horowitz, Rich Zippel, Chtis Terman, Jacob White, Mark Matson, Bob Armstrong, Steve McCormick, Cyrus Bamji, John Wroclawski, Omar Wing, Gary Dare, Paul Bassett, and Rick LaMaire. The author would like to give special thanks to his wife, Deborra, for her support and many contributions to the presentation of this research. The author would also like to thank his parents for their encouragement, and IBM for its financial support of t,I-Jis project through a graduate fellowship. THE BOUNDING APPROACH TO VLSI CIRCUIT SIMULATION 1. INTRODUCTION The VLSI revolution of the 1970's has created a need for new circuit analysis techniques.