Restricted nondeterministic read-once branching programs and an exponential lower bound for integer multiplication

Abstract

Branching programs are a well established computation mo-del for Boolean functions, especially read-once branching programs have been studied intensively. In this paper the expressive power of nondeterministic read-once branching programs, i.e., the class of functions representable in polynomial size, is investigated. For that reason two restricted models of nondeterministic read-once branching programs are defined and a lower bound method is presented. Furthermore, the first exponential lower bound for integer multiplication on the size of a nonde- terministic nonoblivious read-once branching program model is proven.