IM Ken Regan(Kenneth W. Regan is an Associate Professor with tenure in the Department of Computer Science and Engineering, University at Buffalo (SUNY). He works in Computational Complexity Theory and other fields of Information Theory and (Pure) Mathematics that are relevant to this work. He also holds the title of International Master from the World Chess Federation (FIDE), and according to this list can claim to be the highest chess-rated active professional in these fields.), discussing Ken Thompson’s work on chess playing programs.