Published: 31st December 2024
DOI: 10.4204/EPTCS.415
ISSN: 2075-2180

EPTCS 415

Proceedings Eleventh International Conference on
Non-Classical Logics. Theory and Applications
Łódź, Poland, 5-8 September 2024

Edited by: Andrzej Indrzejczak and Michał Zawidzki

Preface
Andrzej Indrzejczak and Michał Zawidzki
Invited Talk: Unorthodox Algebras and Their Associated Logics
Hanamantagouda P. Sankappanavar
1
Invited Talk: Proof Surgeries in Non-Classical Logics
Agata Ciabattoni
2
Invited Talk: CEGAR-Tableaux: Improved Modal Satisfiability for Modal and Tense Logics
Rajeev Goré and Cormac Kikkert
3
Invited Talk: Logics for Strategic Reasoning about Socially Interacting Rational Agents
Valentin Goranko
4
A Binary Quantifier for Definite Descriptions in Nelsonian Free Logic
Yaroslav Petrukhin
5
Twist Sequent Calculi for S4 and its Neighbors
Norihiro Kamide
16
Nested-sequent Calculus for Modal Logic MB
Tomoaki Kawano
33
Two Cases of Deduction with Non-referring Descriptions
Jiří Raclavský
48
Semantic Incompleteness of Liberman et al. (2020)'s Hilbert-style System for Term-modal Logic K with Equality and Non-rigid Terms
Takahiro Sawasaki
66
Agent-Knowledge Logic for Alternative Epistemic Logic
Yuki Nishimura
77
Syntactic Cut-Elimination for Provability Logic GL via Nested Sequents
Akinori Maniwa and Ryo Kashima
93
Incomplete Descriptions and Qualified Definiteness
Bartosz Więckowski
109
Many-Valued Modal Logic
Amir Karniel and Michael Kaminski
121
Modal Logics - RNmatrices vs. Nmatrices
Marcelo E. Coniglio, Paweł Pawłowski and Daniel Skurt
138
Complexity of Nonassociative Lambek Calculus with classical logic
Paweł Płaczek
150
A Unified Gentzen-style Framework for Until-free LTL
Norihiro Kamide and Sara Negri
165
Kamide is in America, Moisil and Leitgeb are in Australia
Satoru Niki and Hitoshi Omori
180
Semi-Substructural Logics à la Lambek
Cheng-Syuan Wan
195
Unified Gentzen Approach to Connexive Logics over Wansing's C
Norihiro Kamide
214
A note on Grigoriev and Zaitsev's system CNL^2_4
Hitoshi Omori and Jonas R. B. Arenhart
229
The Power of Generalized Clemens Semantics
Hitoshi Omori and Jonas R. B. Arenhart
244
The Disjunction-Free Fragment of D2 is Three-Valued
Hitoshi Omori
257

Preface

Non-Classical Logics. Theory and Applications (NCL) is an international conference aimed at presenting novel results and survey works in widely understood non-classical logics and their applications. It was initially held in Łódź, Poland, in September 2008 and 2009. Later on, it was organised alternately in Toruń (2010, 2012, 2015, 2018) and Łódź (2011, 2013, 2016, 2022). The tenth edition of the Conference, organised by the University of Lodz in 2022, was the first one with the Proceedings published in EPTCS. We have a great honour and pleasure to continue this practice and for the second time include all accepted long papers in an EPTCS volume.

This 11th edition is supported by the European Research Council as one of the events organised within the project ExtenDD. In addition to 4 invited talks and 18 contributed talks, we accepted 18 short presentations on the basis of a light reviewing process. This year's edition of NCL was also co-located with the 9th edition of the Workshop on connexive logics and its program included a special session devoted to the presentation of recent results obtained within the project ExtenDD. The conference website can be found at

https://easychair.org/smart-program/NCL'24/.

The Program Committee received about 30 high-quality submissions, which were evaluated on the basis of their significance, novelty and technical correctness. Reviewing was single-blind and each paper was subjected to at least two independent reviews, followed by a thorough discussion within the Program Committee. 18 submissions were selected for presentation on the basis of their quality. This volume contains abstracts of the invited talks and full versions of the accepted submissions.

The Program Committee offered two awards for outstanding submissions. The Best Paper Award went to The Best Paper by a Junior Researcher Award was given to:

The awards have been financially supported by Springer Nature.

We would like to thank all the people who contributed to the successful performance of NCL'24. In particular, we thank the invited speakers for their talks, the authors for their contributed papers and inspiring presentations, the organisers and participants of the workshop, and all participants for their attendance and discussions. We thank the members of the Program Committee and external reviewers for their careful and competent reviewing.

We also greatly appreciate the financial support of the European Research Council, the University of Lodz, and Springer Nature. Last but not least, one of our invited speakers, professor Hanamantagouda P. Sankappanavar, has covered the costs of travel and accommodation for one of the participants of NCL'24.

Program Committee

Local Organizing Committee

External Reviewers


Unorthodox Algebras and Their Associated Logics

Hanamantagouda P. Sankappanavar (Department of Mathematics, State University of New York, New Paltz, NY, USA)

In the first half of my talk, I will introduce five "unorthodox" algebras, four of which have 3-element chain as a lattice-reduct and the fifth one has a 4-element Boolean lattice as a lattice-reduct. These algebras are anti-Boolean and yet have some amazing similarities with Boolean algebras. I develop an algebraic theory of these algebras that leads to an equational axiomatization of the variety 𝕌ℕ𝕆1 generated by the five unorthodox algebras. I, then, look at the structure of the lattice of subvarieties of the variety 𝕌ℕ𝕆1 and provide bases for all 32 subvarieties of 𝕌ℕ𝕆1. I also indicate why these algebras collectively generate a discriminator variety and individually are primal algebras.

In the second half, I will introduce an algebraizable logic (in the sense of Blok and Pigozzi) called "𝒰𝒩𝒪1" whose equivalent algebraic semantics is the variety 𝕌ℕ𝕆1. Here I rely on the well-known results of Rasiowa on implicative logics and of Blok and Pigozzi on algebraizability. I will then present axiomatizations for all the axiomatic extensions of 𝒰𝒩𝒪1 and discuss decidability of these logics.

References

  1. Juan M. Cornejo & Hanamantagouda P. Sankappanavar (2022): A logic for dually hemimorphic semi-Heyting algebras and its axiomatic expansions. Bulletin of the Section of Logic 51(4), pp. 555–645, doi:10.18778/ 0138-0680.2022.23.
  2. Hanamantagouda P. Sankappanavar (1987): Semi-De Morgan algebras. Journal of Symbolic Logic 52(3), pp. 712–724, doi:10.2307/2274359.
  3. Hanamantagouda P. Sankappanavar (2008): Semi-Heyting algebras: An abstraction from Heyting algebras. In M. Abad & I. Viglizzo, editors: Proceedings of the 9th "Dr. Antonio A. R. Monteiro" Congress (Spanish: Actas del IX Congresso Dr. Antonio A. R. Monteiro, held in Bahá Blanca, May 30–June 1, 2007), pp. 33–66.
  4. Hanamantagouda P. Sankappanavar (2011): Expansions of Semi-Heyting algebras I: Discriminator varieties. Studia Logica 98(1–2), pp. 27–81, doi:10.1007/s11225-011-9322-6.
  5. Hanamantagouda P. Sankappanavar (2014): Dually quasi-De Morgan Stone semi-Heyting algebras I: Regularity. Categories, General Algebraic Structures and Applications 2(1), pp. 47–64.

Proof Surgeries in Non-Classical Logics

Agata Ciabattoni (Vienna University of Technology, Austria)

This talk explores global proof transformations within sequent and hypersequent calculi. These transformations result in:

  1. restricting cuts to analytic cuts,
  2. replacing hypersequent structures with bounded cuts, and
  3. eliminating the density rule from hypersequent calculi (thus determining whether a given logic qualifies as a fuzzy logic).

CEGAR-Tableaux: Improved Modal Satisfiability for Modal and Tense Logics

Rajeev Goré (Australian National University, Canberra, Australia)
Cormac Kikkert

CEGAR-tableaux utilise SAT-solvers and modal clause learning to give the current state-of-the-art satisfiability checkers for basic modal logics K, KT and S4. I will start with a brief overview of the basic CEGAR-tableaux method for these logics.

I will show how to extend CEGAR-Tableaux to handle the five basic extensions of K by the axioms D, T, B, 4 and 5, and then indirectly to the whole modal cube. Experiments confirm that the resulting satisfiability-checkers are also the current best ones for these logics.

I will show how to extend CEGAR-tableaux to handle the modal tense logic Kt, which involves modalities for the "future" and the "past". Once again, our experiments show that CEGAR-tableaux are state-of-the-art for these logics.

The talk is intended as an exposition for a broad audience and does not require any knowledge of SAT-solvers or computer science but some knowledge of modal logic would help.


Logics for Strategic Reasoning about Socially Interacting Rational Agents

Valentin Goranko (Stockholm University, Sweden)

This work is on using formal logic for capturing reasoning about strategic abilities of rational agents and groups (coalitions) of agents to guarantee achievement of their goals, while acting and interacting within a society of agents. That strategic interaction can be quite complex, as it usually involves various patterns combining cooperation and competition.

The earliest logical systems for formalizing strategic reasoning include Coalition Logic (CL) introduced and studied by Pauly in the early 2000s and the independently introduced and studied at about the same period by Alur, Henzinger and Kupferman Alternating Time Temporal Logic ATL.

Recently more expressive and versatile logical systems, capturing the reasoning about strategic abilities of socially interacting rational agents and coalitions, have been proposed and studied, including:

  1. the Socially Friendly Coalition Logic (SFCL), enabling formal reasoning about strategic abilities of individuals and groups to ensure achievement of their private goals while allowing for cooperation with the entire society;
  2. the Logic of Coalitional Goal Assignments (LCGA), capturing reasoning about strategic abilities of the entire society to cooperate in order to ensure achievement of the societal goals, while protecting the abilities of individuals and groups within the society to achieve their individual and group goals;
  3. the Logic for Conditional Strategic Reasoning (ConStR), formalising reasoning about agents' strategic abilities conditional on the goals of the other agents and on the actions that they are expected to take in pursuit of these goals.

Paper [1] provides a recent overview of these.

References

[1] Valentin Goranko (2023): Logics for Strategic Reasoning of Socially Interacting Rational Agents: An Overview and Perspectives. Logics 1(1), pp. 4–35, doi:10.3390/logics1010003. Available at https: //www.mdpi.com/2813-0405/1/1/3.