In preparation
On Variable Non-Dependence of First-Order Formulas
- Koen Lefever and Gergely Székely
- Preprint (2025):
- Currently under peer-review
International peer-reviewed publications
Distances between formal theories
- Mohamed Khaled, Gergely Székely, Koen Lefever and Michèle Friend
- Published in The Review of Symbolic Logic, Volume 14 Issue 3 pages 633-654, September 2020 (online 04 October 2019)
- DOI: 10.1017/S1755020319000558
- Postprint (PDF): post-peer-review, pre-copyedit version
- Preprint:
- Cited in:
- Definable coordinate geometries over fields, part 2: Applications (arXiv:2507.10289) by Judit Madarász, Mike Stannett and Gergely Székely (2025)
- Definable coordinate geometries over fields, part 1: Theory (arXiv:2507.10279) by Judit Madarász, Mike Stannett and Gergely Székely (2025)
- On the networks of large embeddings by Tuğba Aslan, Mohamed Khaled and Gergely Székely in Algebra universalis 85(3) (2024)
- Felix Lev. Finite Mathematics as the Foundation of Classical Mathematics and Quantum Theory by Jean Paul Van Bendegem in Philosophia Mathematica (2024)
- Conceptual Distance and Algebras of Concepts by Mohamed Khaled and Gergely Székely in The Review of Symbolic Logic (2024)
- Modal Logics That Are Both Monotone and Antitone: Makinson’s Extension Results and Affinities between Logics by Lloyd Humberstone and Steven T. Kuhn in Notre Dame Journal of Formal Logic. Volume: 63. Issue: 4. (2022)
- In the Footsteps of Hilbert: The Andréka-Németi Group's Logical Foundations of Theories in Physics by Giambattista Formica and Michèle Friend in: Hajnal Andréka and István Németi on Unity of Science, editors: Judit Madarász and Gergely Székely (2021)
- Algebras of Concepts and Their Networks by Mohamed Khaled and Gergely Székely, in: Allahviranloo, T., Salahshour, S., Arica, N. (eds) Progress in Intelligent Decision Science. IDS 2020. Advances in Intelligent Systems and Computing, vol 1301. Springer, Cham. (2021)
- Two-variable logic has weak, but not strong, Beth definability (arXiv:2010.00901) by Hajnal Andréka & István Németi (2020)
- One-Shot Induction of Generalized Logical Concepts via Human Guidance (arXiv:1912.07060) by Mayukh Das, Nandini Ramanan, Janardhan Rao Doppa & Sriraam Natarajan (2019)
- Human-Allied Efficient and Effective Learning in Noisy Domains by Mayukh Das (2019)
On Generalization of Definitional Equivalence to Non-Disjoint Languages
Comparing Classical And Relativistic Kinematics In First-Order Logic
Non-peer-reviewed publications
Interview met Ann Vanreusel over ecologie van de zeebodem - Entretien avec Ann Vanreusel à propos de l’écologie des fonds marins
- Koen Lefever
- Interview with Prof. Dr. Ann Vanreusel (Marine Biology, Ghent University) on seabed ecology
- Published in Science Connection 68, pages 23-26, June-October 2022
- Download PDF:
Book chapter
Égalité: Symbolen in de Logika en in de Vrijmetselarij
(Equality: Symbols in Logic and in Freemasonry)
- Koen Lefever
- Published in: Bart Van Kerkhove, Karen François, Steffen Ducheyne, and Patrick Allo (editors) "Laat ons niet ernstig blijven ∞ Huldeboek voor Jean Paul Van Bendegem" (Liber amicorum for Prof. Dr. Em. Jean Paul Van Bendegem), pp. 209-223, Academia Press, Ghent (2018)
- ISBN: 978 94 014 5589 3
- Download PDF (in Dutch)
PhD Dissertation
Using Logical Interpretation and Definitional Equivalence to Compare Classical Kinematics and Special Relativity Theory
- Koen Lefever
- Vrije Universiteit Brussel (2017)
- Supervisors: prof. dr. Jean Paul Van Bendegem and dr. Gergely Székely
- Download dissertation as PDF
- Cited in:
- On Andréka's conjecture that Special Relativity is the only possible conceptual reduct of Classical Kinematics (arXiv:2507.21180) by Judit Madarász, Mike Stannett and Gergely Székely (2025)
- Definable coordinate geometries over fields, part 2: applications (arXiv:2507.10289) by Judit Madarász, Mike Stannett and Gergely Székely (2025)
- Conceptual Distance and Algebras of Concepts by Mohamed Khaled and Gergely Székely in The Review of Symbolic Logic (2024)
- Investigations of isotropy and homogeneity of spacetime in first-order logic by Judit X. Madarász, Mike Stannett and Gergely Székely in Annals of Pure and Applied Logic, Volume 173, Issue 9, October–November 2022
- In the Footsteps of Hilbert: The Andréka-Németi Group's Logical Foundations of Theories in Physics by Giambattista Formica and Michèle Friend in: Hajnal Andréka and István Németi on Unity of Science, editors: Judit Madarász and Gergely Székely (2021)
- Mathematical Theories as Models by Michèle Friend in: Humanizing Mathematics and its Philosophy; Essays Celebrating the 90th Birthday of Reuben Hersh, editor: Baharath Sriraman, Birkhäuser (2017)
Master's Thesis
Logische en ontologische aspekten van ruimte en tijd in axiomatieken voor de speciale relativiteitstheorie
(Logical and ontological aspects of space and time in axiom systems for special relativity theory)
