2019-08-16: Rob Myers

Sat, 21 Oct 2023 21:24:08 +0100

Rob Myers

Polynomial certificates for nondeterministic automata

Abstract

Given a deterministic finite automaton accepting L, another accepting the reverse language, and an integer n, does there exist a nondeterministic acceptor with n or fewer states? We've proved that this problem is in NP i.e. polynomial certificates exist. All previous algorithms constructing small nondeterministic automata for arbitrary regular languages are at best PSPACE-complete. We achieve this by explaining and substantially improving the Kameda-Weiner algorithm using coalgebraic methods. At the underlying level we use a categorical equivalence between finite join-semilattices and bipartitioned graphs.

2019-08-16 16:00:00 UTC
LT1415