Branching Programs are, besides Boolean circuits, the most important nonuniform model of computation. This volume gives a survey of the latest research in this field. It presents a branching program-based approach to complexity theory. Starting with a definition of branching programs and a review of the former research, nondeterministic branching programs are introduced and investigated, thus allowing the description of some fundamental complexity classes. The book then concentrates on the new concept of Omega-branching programs. Apart from the usual binary tests they contain features for evaluating certain elementary Boolean functions and are suited for characterizing space-bounded complexity classes. By means of these characterizations the author demonstrates the separation of some restricted complexity classes. In the appendix a number of extremely restricted graph-accessibility problems are given, which are, due to the branching program descriptions in chapters 1-3, p-projection complete in the classes under consideration. Preliminaries.- Branching programs and their computational power.- Nondeterministic branching programs.- ?=branching programs and theirs computational power. Christoph Meinel is the Founding President of the German University of Digital Sciences and previously has been Director and CEO of the Hasso Plattner Institute. He heads the Internet Technologies and Systems department and is author of numerous scientific publications, developer of large digital systems, such as openHPI.de and HPI Schul-Cloud, and a sought-after consultant for politics and business.Maxim Asjoma is Head of Public Partnerships at Hasso Plattner Institute and holds a doctorate in philosophy with a specialization in economics and digitalization. The focus of his work interest is how digital technologies are transforming societies.
