Principles of Random Walk (2nd ed.)

In this edition a large number of errors have been corrected, an occasional proof has been streamlined, and a number of references are made to recent pro­ gress. These references are to a supplementary bibliography, whose items are referred to as [S1] through [S26]. A thorough revision was not attempted. The development of the subject in the last decade would have required a treatment in a much more general con­ text. It is true that a number of interesting questions remain open in the concrete