---
_id: '13292'
abstract:
- lang: eng
  text: The operator precedence languages (OPLs) represent the largest known subclass
    of the context-free languages which enjoys all desirable closure and decidability
    properties. This includes the decidability of language inclusion, which is the
    ultimate verification problem. Operator precedence grammars, automata, and logics
    have been investigated and used, for example, to verify programs with arithmetic
    expressions and exceptions (both of which are deterministic pushdown but lie outside
    the scope of the visibly pushdown languages). In this paper, we complete the picture
    and give, for the first time, an algebraic characterization of the class of OPLs
    in the form of a syntactic congruence that has finitely many equivalence classes
    exactly for the operator precedence languages. This is a generalization of the
    celebrated Myhill-Nerode theorem for the regular languages to OPLs. As one of
    the consequences, we show that universality and language inclusion for nondeterministic
    operator precedence automata can be solved by an antichain algorithm. Antichain
    algorithms avoid determinization and complementation through an explicit subset
    construction, by leveraging a quasi-order on words, which allows the pruning of
    the search space for counterexample words without sacrificing completeness. Antichain
    algorithms can be implemented symbolically, and these implementations are today
    the best-performing algorithms in practice for the inclusion of finite automata.
    We give a generic construction of the quasi-order needed for antichain algorithms
    from a finite syntactic congruence. This yields the first antichain algorithm
    for OPLs, an algorithm that solves the ExpTime-hard language inclusion problem
    for OPLs in exponential time.
acknowledgement: "This work was supported in part by the ERC-2020-AdG 101020093.\r\nWe
  thank Pierre Ganty for early discussions and the anonymous reviewers for their helpful
  comments.\r\n"
alternative_title:
- LIPIcs
article_processing_charge: Yes
arxiv: 1
author:
- first_name: Thomas A
  full_name: Henzinger, Thomas A
  id: 40876CD8-F248-11E8-B48F-1D18A9856A87
  last_name: Henzinger
  orcid: 0000-0002-2985-7724
- first_name: Pavol
  full_name: Kebis, Pavol
  last_name: Kebis
- first_name: Nicolas Adrien
  full_name: Mazzocchi, Nicolas Adrien
  id: b26baa86-3308-11ec-87b0-8990f34baa85
  last_name: Mazzocchi
- first_name: Naci E
  full_name: Sarac, Naci E
  id: 8C6B42F8-C8E6-11E9-A03A-F2DCE5697425
  last_name: Sarac
citation:
  ama: 'Henzinger TA, Kebis P, Mazzocchi NA, Sarac NE. Regular methods for operator
    precedence languages. In: <i>50th International Colloquium on Automata, Languages,
    and Programming</i>. Vol 261. Schloss Dagstuhl - Leibniz-Zentrum für Informatik;
    2023:129:1--129:20. doi:<a href="https://doi.org/10.4230/LIPIcs.ICALP.2023.129">10.4230/LIPIcs.ICALP.2023.129</a>'
  apa: 'Henzinger, T. A., Kebis, P., Mazzocchi, N. A., &#38; Sarac, N. E. (2023).
    Regular methods for operator precedence languages. In <i>50th International Colloquium
    on Automata, Languages, and Programming</i> (Vol. 261, p. 129:1--129:20). Paderborn,
    Germany: Schloss Dagstuhl - Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPIcs.ICALP.2023.129">https://doi.org/10.4230/LIPIcs.ICALP.2023.129</a>'
  chicago: Henzinger, Thomas A, Pavol Kebis, Nicolas Adrien Mazzocchi, and Naci E
    Sarac. “Regular Methods for Operator Precedence Languages.” In <i>50th International
    Colloquium on Automata, Languages, and Programming</i>, 261:129:1--129:20. Schloss
    Dagstuhl - Leibniz-Zentrum für Informatik, 2023. <a href="https://doi.org/10.4230/LIPIcs.ICALP.2023.129">https://doi.org/10.4230/LIPIcs.ICALP.2023.129</a>.
  ieee: T. A. Henzinger, P. Kebis, N. A. Mazzocchi, and N. E. Sarac, “Regular methods
    for operator precedence languages,” in <i>50th International Colloquium on Automata,
    Languages, and Programming</i>, Paderborn, Germany, 2023, vol. 261, p. 129:1--129:20.
  ista: 'Henzinger TA, Kebis P, Mazzocchi NA, Sarac NE. 2023. Regular methods for
    operator precedence languages. 50th International Colloquium on Automata, Languages,
    and Programming. ICALP: Automata, Languages and Programming, LIPIcs, vol. 261,
    129:1--129:20.'
  mla: Henzinger, Thomas A., et al. “Regular Methods for Operator Precedence Languages.”
    <i>50th International Colloquium on Automata, Languages, and Programming</i>,
    vol. 261, Schloss Dagstuhl - Leibniz-Zentrum für Informatik, 2023, p. 129:1--129:20,
    doi:<a href="https://doi.org/10.4230/LIPIcs.ICALP.2023.129">10.4230/LIPIcs.ICALP.2023.129</a>.
  short: T.A. Henzinger, P. Kebis, N.A. Mazzocchi, N.E. Sarac, in:, 50th International
    Colloquium on Automata, Languages, and Programming, Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2023, p. 129:1--129:20.
conference:
  end_date: 2023-07-14
  location: Paderborn, Germany
  name: 'ICALP: Automata, Languages and Programming'
  start_date: 2023-07-10
corr_author: '1'
date_created: 2023-07-24T15:11:41Z
date_published: 2023-07-05T00:00:00Z
date_updated: 2025-07-10T11:50:41Z
day: '05'
ddc:
- '000'
department:
- _id: GradSch
- _id: ToHe
doi: 10.4230/LIPIcs.ICALP.2023.129
ec_funded: 1
external_id:
  arxiv:
  - '2305.03447'
file:
- access_level: open_access
  checksum: 5d4c8932ef3450615a53b9bb15d92eb2
  content_type: application/pdf
  creator: esarac
  date_created: 2023-07-24T15:11:05Z
  date_updated: 2023-07-24T15:11:05Z
  file_id: '13293'
  file_name: icalp23.pdf
  file_size: 859379
  relation: main_file
  success: 1
file_date_updated: 2023-07-24T15:11:05Z
has_accepted_license: '1'
intvolume: '       261'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
page: 129:1--129:20
project:
- _id: 62781420-2b32-11ec-9570-8d9b63373d4d
  call_identifier: H2020
  grant_number: '101020093'
  name: Vigilant Algorithmic Monitoring of Software
publication: 50th International Colloquium on Automata, Languages, and Programming
publication_identifier:
  eissn:
  - 1868-8969
  isbn:
  - '9783959772785'
publication_status: published
publisher: Schloss Dagstuhl - Leibniz-Zentrum für Informatik
quality_controlled: '1'
scopus_import: '1'
status: public
title: Regular methods for operator precedence languages
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: 261
year: '2023'
...
