---
_id: '10075'
abstract:
- lang: eng
  text: We study the expressiveness and succinctness of good-for-games pushdown automata
    (GFG-PDA) over finite words, that is, pushdown automata whose nondeterminism can
    be resolved based on the run constructed so far, but independently of the remainder
    of the input word. We prove that GFG-PDA recognise more languages than deterministic
    PDA (DPDA) but not all context-free languages (CFL). This class is orthogonal
    to unambiguous CFL. We further show that GFG-PDA can be exponentially more succinct
    than DPDA, while PDA can be double-exponentially more succinct than GFG-PDA. We
    also study GFGness in visibly pushdown automata (VPA), which enjoy better closure
    properties than PDA, and for which we show GFGness to be ExpTime-complete. GFG-VPA
    can be exponentially more succinct than deterministic VPA, while VPA can be exponentially
    more succinct than GFG-VPA. Both of these lower bounds are tight. Finally, we
    study the complexity of resolving nondeterminism in GFG-PDA. Every GFG-PDA has
    a positional resolver, a function that resolves nondeterminism and that is only
    dependant on the current configuration. Pushdown transducers are sufficient to
    implement the resolvers of GFG-VPA, but not those of GFG-PDA. GFG-PDA with finite-state
    resolvers are determinisable.
acknowledgement: 'Ismaël Jecker: Funded by the European Union’s Horizon 2020 research
  and innovation programme under the Marie Skłodowska-Curie grant agreement No 754411.
  Karoliina Lehtinen: Funded by the European Union’s Horizon 2020 research and innovation
  programme under the Marie Skłodowska-Curie grant agreement No 892704.'
alternative_title:
- LIPIcs
article_number: '53'
article_processing_charge: No
arxiv: 1
author:
- first_name: Shibashis
  full_name: Guha, Shibashis
  last_name: Guha
- first_name: Ismael R
  full_name: Jecker, Ismael R
  id: 85D7C63E-7D5D-11E9-9C0F-98C4E5697425
  last_name: Jecker
- first_name: Karoliina
  full_name: Lehtinen, Karoliina
  last_name: Lehtinen
- first_name: Martin
  full_name: Zimmermann, Martin
  last_name: Zimmermann
citation:
  ama: 'Guha S, Jecker IR, Lehtinen K, Zimmermann M. A bit of nondeterminism makes
    pushdown automata expressive and succinct. In: <i>46th International Symposium
    on Mathematical Foundations of Computer Science</i>. Vol 202. Schloss Dagstuhl
    - Leibniz Zentrum für Informatik; 2021. doi:<a href="https://doi.org/10.4230/LIPIcs.MFCS.2021.53">10.4230/LIPIcs.MFCS.2021.53</a>'
  apa: 'Guha, S., Jecker, I. R., Lehtinen, K., &#38; Zimmermann, M. (2021). A bit
    of nondeterminism makes pushdown automata expressive and succinct. In <i>46th
    International Symposium on Mathematical Foundations of Computer Science</i> (Vol.
    202). Tallinn, Estonia: Schloss Dagstuhl - Leibniz Zentrum für Informatik. <a
    href="https://doi.org/10.4230/LIPIcs.MFCS.2021.53">https://doi.org/10.4230/LIPIcs.MFCS.2021.53</a>'
  chicago: Guha, Shibashis, Ismael R Jecker, Karoliina Lehtinen, and Martin Zimmermann.
    “A Bit of Nondeterminism Makes Pushdown Automata Expressive and Succinct.” In
    <i>46th International Symposium on Mathematical Foundations of Computer Science</i>,
    Vol. 202. Schloss Dagstuhl - Leibniz Zentrum für Informatik, 2021. <a href="https://doi.org/10.4230/LIPIcs.MFCS.2021.53">https://doi.org/10.4230/LIPIcs.MFCS.2021.53</a>.
  ieee: S. Guha, I. R. Jecker, K. Lehtinen, and M. Zimmermann, “A bit of nondeterminism
    makes pushdown automata expressive and succinct,” in <i>46th International Symposium
    on Mathematical Foundations of Computer Science</i>, Tallinn, Estonia, 2021, vol.
    202.
  ista: 'Guha S, Jecker IR, Lehtinen K, Zimmermann M. 2021. A bit of nondeterminism
    makes pushdown automata expressive and succinct. 46th International Symposium
    on Mathematical Foundations of Computer Science. MFCS: Mathematical Foundations
    of Computer Science, LIPIcs, vol. 202, 53.'
  mla: Guha, Shibashis, et al. “A Bit of Nondeterminism Makes Pushdown Automata Expressive
    and Succinct.” <i>46th International Symposium on Mathematical Foundations of
    Computer Science</i>, vol. 202, 53, Schloss Dagstuhl - Leibniz Zentrum für Informatik,
    2021, doi:<a href="https://doi.org/10.4230/LIPIcs.MFCS.2021.53">10.4230/LIPIcs.MFCS.2021.53</a>.
  short: S. Guha, I.R. Jecker, K. Lehtinen, M. Zimmermann, in:, 46th International
    Symposium on Mathematical Foundations of Computer Science, Schloss Dagstuhl -
    Leibniz Zentrum für Informatik, 2021.
conference:
  end_date: 2021-08-27
  location: Tallinn, Estonia
  name: 'MFCS: Mathematical Foundations of Computer Science'
  start_date: 2021-08-23
date_created: 2021-10-03T22:01:23Z
date_published: 2021-08-18T00:00:00Z
date_updated: 2022-05-13T08:21:56Z
day: '18'
ddc:
- '000'
department:
- _id: KrCh
doi: 10.4230/LIPIcs.MFCS.2021.53
ec_funded: 1
external_id:
  arxiv:
  - '2105.02611'
file:
- access_level: open_access
  checksum: f4d407d43a97330c3fb11e6a7a6fbfb2
  content_type: application/pdf
  creator: cchlebak
  date_created: 2021-10-06T12:44:05Z
  date_updated: 2021-10-06T12:44:05Z
  file_id: '10097'
  file_name: 2021_LIPIcs_Guha.pdf
  file_size: 825567
  relation: main_file
  success: 1
file_date_updated: 2021-10-06T12:44:05Z
has_accepted_license: '1'
intvolume: '       202'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '08'
oa: 1
oa_version: Published Version
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '754411'
  name: ISTplus - Postdoctoral Fellowships
publication: 46th International Symposium on Mathematical Foundations of Computer
  Science
publication_identifier:
  isbn:
  - 978-3-9597-7201-3
  issn:
  - 1868-8969
publication_status: published
publisher: Schloss Dagstuhl - Leibniz Zentrum für Informatik
quality_controlled: '1'
scopus_import: '1'
status: public
title: A bit of nondeterminism makes pushdown automata expressive and succinct
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 202
year: '2021'
...
