Contradictory Logics: A Radical Challenge to Logical Orthodoxy

Project Information

ConLog

Grant agreement ID: 101018280

DOI

10.3030/101018280

EC signature date 24 July 2021

Start date 1 October 2021

End date 30 September 2026

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 2 059 026,00

EU contribution

€ 2 059 026,00

Coordinated by

RUHR-UNIVERSITAET BOCHUM
Germany

CORDIS provides links to public deliverables and publications of HORIZON projects.

Links to deliverables and publications from FP7 projects, as well as links to some specific result types such as dataset and software, are dynamically retrieved from OpenAIRE .

Publications

Peer reviewed articles (25)

On the completeness of some first-order extensions of C

Author(s): Grigory Olkhovikov
Published in: Journal of Applied Logics - IfCoLog Journal, Issue 10 (1), 2023, Page(s) 57 -114, ISSN 2055-3714
Publisher: College Publications on behalf of the UK logic charity IfCoLog
DOI: 10.13154/294-9815

Kamide is in America, Moisil and Leitgeb are in Australia

Author(s): Satoru Niki, Hitoshi Omori
Published in: Electronic Proceedings in Theoretical Computer Science, Issue 415, 2025, Page(s) 180-194, ISSN 2075-2180
Publisher: Open Publishing Association
DOI: 10.4204/eptcs.415.17

BI-CONNEXIVE LOGIC, BILATERALISM, AND NEGATION INCONSISTENCY

Author(s): HEINRICH WANSING, SATORU NIKI, SERGEY DROBYSHEVICH
Published in: The Review of Symbolic Logic, Issue 18, 2025, Page(s) 859-899, ISSN 1755-0203
Publisher: Cambridge University Press
DOI: 10.1017/s1755020324000248

Queer feminist logic and contradictions: Or how logic and feminism can be relevant to each other

Author(s): Sara Ayhan
Published in: Synthese, Issue 206, 2025, ISSN 1573-0964
Publisher: Springer Science and Business Media LLC
DOI: 10.1007/s11229-025-05220-2

Connexive Exclusion

Author(s): Yaroslav Shramko, Heinrich Wansing
Published in: Erkenntnis, Issue 90, 2025, Page(s) 3371-3402, ISSN 0165-0106
Publisher: Reidel
DOI: 10.1007/s10670-024-00842-3

Logical multilateralism

Author(s): Heinrich Wansing; Sara Ayhan
Published in: Journal of Philosophical Logic, Issue 52, 2023, Page(s) 1603–1636, ISSN 1573-0433
Publisher: Springer Nature
DOI: 10.1007/s10992-023-09720-9

Constructive Logic is Connexive and Contradictory

Author(s): Heinrich Wansing
Published in: Logic and Logical Philosophy, Issue 34, 2024, Page(s) 1-27, ISSN 1425-3305
Publisher: Nicolaus Copernicus University
DOI: 10.12775/llp.2024.001

On the provable contradictions of the connexive logics C and C3

Author(s): Satoru Niki; Heinrich Wansing
Published in: Journal of Philosophical Logic, Issue 52, 2023, Page(s) 1355–1383,, ISSN 1573-0433
Publisher: Springert Nature
DOI: 10.1007/s10992-023-09709-4

Problems and Consequences of Bilateral Notions of (Meta-)Derivability

Author(s): Sara Ayhan
Published in: Erkenntnis, 2025, ISSN 0165-0106
Publisher: Reidel
DOI: 10.1007/s10670-025-01004-9

"A note on ""A Connexive Conditional"""

Author(s): Heinrich Wansing; Hitoshi Omori
Published in: Logos & Episteme, Issue 13, 2022, Page(s) 325-328, ISSN 2069-3052
Publisher: Institute for Economic and Social Research, Romania
DOI: 10.13154/294-9816

Connexive Logic, Connexivity, and Connexivism: Remarks on Terminology

Author(s): Heinrich Wansing; Hitoshi Omori
Published in: Studia Logica, Issue 112, 2023, Page(s) 1-35, ISSN 1572-8730
Publisher: Springer Nature
DOI: 10.1007/s11225-023-10082-1

One heresy and one orthodoxy: On dialetheism, dimathematism, and the non-normativity of logic

Author(s): Heinrich Wansing
Published in: Erkenntnis, Issue 89, 2024, Page(s) 181–205, ISSN 0165-0106
Publisher: Reidel
DOI: 10.1007/s10670-022-00528-8

Intuitionistic views on connexive constructible falsity

Author(s): Satoru Niki
Published in: Journal of Applied Logics - IfCoLog Journal, Issue 11, 2024, Page(s) 125–157, ISSN 2055-3714
Publisher: College Publications on behalf of the UK logic charity IfCoLog
DOI: 10.13154/294-12564

An Intuitionistically Complete System of Basic Intuitionistic Conditional Logic

Author(s): Grigory Olkhovikov
Published in: Journal of Philosophical Logic, Issue 53, 2024, Page(s) 1199-1240, ISSN 0022-3611
Publisher: Kluwer Academic Publishers
DOI: 10.1007/s10992-024-09763-6

Proof-Theoretic Functional Completeness for the Connexive Logic C

Author(s): Sara Ayhan, Hrafn Valtýr Oddsson
Published in: Studia Logica, 2025, ISSN 0039-3215
Publisher: Kluwer Academic Publishers
DOI: 10.1007/s11225-025-10200-1

CONDITIONAL REASONING AND THE SHADOWS IT CASTS ONTO THE FIRST-ORDER LOGIC: THE NELSONIAN CASE

Author(s): GRIGORY OLKHOVIKOV
Published in: The Bulletin of Symbolic Logic, 2026, Page(s) 1-61, ISSN 1079-8986
Publisher: Cambridge University Press (CUP)
DOI: 10.1017/bsl.2025.10136

A basic system of paraconsistent Nelsonian logic of conditionals

Author(s): Grigory K. Olkhovikov
Published in: Journal of Logic, Language and Information, Issue 33, 2024, Page(s) 299-337, ISSN 0925-8531
Publisher: Kluwer Academic Publishers
DOI: 10.1007/s10849-024-09421-9

CONTRADICTIONS WITHOUT NEGATION AND A PROOF-THEORETIC, BILATERALIST ACCOUNT OF CONNEXIVE LOGICS

Author(s): SARA AYHAN
Published in: The Review of Symbolic Logic, 2026, Page(s) 1-28, ISSN 1755-0203
Publisher: Cambridge University Press
DOI: 10.1017/s1755020326101063

Abelian Logic on the Bochum Plan (and the American Plan as Well)

Author(s): Satoru Niki, Heinrich Wansing
Published in: Studia Logica, 2025, ISSN 0039-3215
Publisher: Kluwer Academic Publishers
DOI: 10.1007/s11225-025-10208-7

Notions of Proof and Refutation in ‘Gentzensemantik’: Franz von Kutschera as an Early Proponent of (Bilateralist) Proof-Theoretic Semantics

Author(s): Sara Ayhan
Published in: History and Philosophy of Logic, Issue 46, 2025, Page(s) 449-455, ISSN 0144-5340
Publisher: Abacus Press
DOI: 10.1080/01445340.2024.2393964

Double negation as minimal negation

Author(s): Satoru Niki
Published in: Journal of Logic, Language and Information, Issue 35, 2023, Page(s) 861-886, ISSN 0925-8531
Publisher: Kluwer Academic Publishers
DOI: 10.1007/s10849-023-09413-1

Quantifiers in connexive logic (in general and in particular)

Author(s): Heinrich Wansing, Zach Weber
Published in: Logic Journal of the IGPL, Issue 33, 2025, Page(s) 22 pp., ISSN 1367-0751
Publisher: Oxford University Press
DOI: 10.1093/jigpal/jzae115

On synonymy in proof-theoretic semantics. The case of 2Int

Author(s): Sara Ayhan; Heinrich Wansing
Published in: Bulletin of the Section of Logic, Issue 52, 2023, Page(s) 187–237, ISSN 2449-836X
Publisher: Lodz University Press
DOI: 10.18778/0138-0680.2023.18

Note on Contradictions in Francez-Weiss Logics

Author(s): Satoru Niki
Published in: Logic and Logical Philosophy, Issue 34, 2024, Page(s) 1-30, ISSN 1425-3305
Publisher: Nicolaus Copernicus University
DOI: 10.12775/llp.2024.031

A note on negation inconsistent variants of FDE-negation

Author(s): Satoru Niki
Published in: Australasian Journal of Logic, Issue 21, 2024, Page(s) 65-90, ISSN 1448-5052
Publisher: Victoria Univertsity of Wellington
DOI: 10.13154/294-12618

Book chapters (5)

Varieties of negation and contra-classicality in view of Dunn semantics

Author(s): Hitoshi Omori; Heinrich Wansing
Published in: Relevance Logics and other Tools for Reasoning : Essays in Honour of Michael Dunn, 2022, Page(s) 309-337, ISBN 978-1-84890-395-1
Publisher: College Publications
DOI: 10.13154/294-10519

A Note on the Historiography of Pre-modern Connexive Logic

Author(s): Heinrich Wansing, Hitoshi Omori
Published in: Trends in Logic, 60 Years of Connexive Logic, 2025, Page(s) 1-22
Publisher: Springer Nature Switzerland
DOI: 10.1007/978-3-031-82994-9_1

Remarks on Semantic Information and Logic. From Semantic Tetralateralism to the Pentalattice 65536_5

Author(s): Heinrich Wansing
Published in: Logica Yearbook 2022, 2023, Page(s) 165-186, ISBN 978-1-84890-446-0
Publisher: College Publications
DOI: 10.13154/294-12570

Ten Open Problems in Connexive Logic

Author(s): Hitoshi Omori, Heinrich Wansing
Published in: Trends in Logic, 60 Years of Connexive Logic, 2025, Page(s) 241-252
Publisher: Springer Nature Switzerland
DOI: 10.1007/978-3-031-82994-9_10

Another Generalization of Connexive Logic C

Author(s): Hitoshi Omori, Heinrich Wansing
Published in: Trends in Logic, 60 Years of Connexive Logic, 2025, Page(s) 225-240
Publisher: Springer Nature Switzerland
DOI: 10.1007/978-3-031-82994-9_9