Summary: The Satisfiability Problem for
Probabilistic Ordered Branching Programs
Dept. of Computer Science
Indian Institute of Technology
Kanpur 208016, India
Abt. Theoretische Informatik
89069 Ulm, Germany
We show that the satisfiability problem for bounded-error proba-
bilistic ordered branching programs is NP-complete. If the error is
very small, however (more precisely, if the error is bounded by the
reciprocal of the width of the branching program), then we have a
polynomial-time algorithm for the satisfiability problem.
Branching programs are an interesting computational model to investigate.
One reason for this is the tight relationship of the size of a branching program
to the space needed by (nonuniform) Turing machines [Mas76] (see [BS90]).