Algorithms are a set of rules that specify a sequence of actions to be taken to solve a problem. Distributed algorithms, which are designed to solve many problems at once, are conceptually far more complex than algorithms in a single processing unit environment. When the number of simultaneous events becomes large, human minds cannot keep track of all of them. Naturally, it is necessary to know whether a distributed algorithm will have the desired effect. In this book, Dr. Schoone discusses assertational verification by system-wide invariants for use in verifying the behavior of distributed algorithms. The approach is entirely pragmatic; the author considers many different examples, over a wide range of algorithms and protocols. This volume will be an essential purchase for all those with an interest in distributed algorithms.