A1 Refereed original research article in a scientific journal

Descriptional complexity of unambiguous input-driven pushdown automata




AuthorsAlexander Okhotin, Kai Salomaa

PublisherELSEVIER SCIENCE BV

Publication year2015

JournalTheoretical Computer Science

Journal name in sourceTHEORETICAL COMPUTER SCIENCE

Journal acronymTHEOR COMPUT SCI

Volume566

First page 1

Last page11

Number of pages11

ISSN0304-3975

DOIhttps://doi.org/10.1016/j.tcs.2014.11.015


Abstract

It is known that a nondeterministic input-driven pushdown automaton (IDPDA) (a.k.a. visibly pushdown automaton; a.k.a. nested word automaton) with n states can be transformed to an equivalent deterministic automaton with 2(Theta(n2)) states (B. von Braunmuhl and R. Verbeek, 1983 [8]), and that this size is necessary in the worst case (R. Alur and P. Madhusudan, 2009 [4]). This paper demonstrates that the same worst-case 2(Theta(n2)) size blow-up occurs when converting a nondeterministic IDPDA to an unambiguous one, and an unambiguous IDPDA to a deterministic one. In addition, the methods developed in this paper are used to demonstrate that the descriptional complexity of complementation for nondeterministic IDPDAs is 2(Theta(n2)), and that the descriptional complexity of homomorphisms for deterministic IDPDAs is 2(Theta(n2)).




Last updated on 2024-26-11 at 15:44