Wykłady w ramach seminarium Logica Copernicana
Zapraszamy na kolejne wykłady w ramach seminarium naukowego Logica Copernicana, organizowanego przez Katedrę Logiki UMK. Podczas najbliższych spotkań referaty wygłoszą badacze z Uniwersytetu im. Adama Mickiewicza w Poznaniu: prof. Dorota Leszczyńska-Jasion, dr Szymon Chlebowski oraz Wiktor Nowicki.
Plan wykładów jest następujący:
Dr Szymon Chlebowski, 27.04.2026 o godzinie 09.00 w Katedrze Logiki.
Tytuł wystąpienia: Why study non-Fregeanity today?
Abstrakt: The aim of this talk is to look at non-Fregean logics from a bird’s-eye perspective. We argue that the notion of non-Fregeanity (understood in line with Roman Suszko’s original intentions) is closely related to several important concepts in contemporary logic and type theory. We show how some ideas rooted in Suszko's approach to logic can shed light on these concepts. We will especially focus on non-Fregeanity in the context of constructive logics.
Prof. Dorota Leszczyńska-Jasion, 28.04.2026 o godzinie 09.00 w Katedrze Logiki.
Tytuł wystąpienia: Kripke semantics for some weak modal logics with non-Fregean identity
Abstrakt: The goal of my work is a unifying Kripke-semantic account of some non-Fregean logics and weak modal logics. The logics in question are Suszko's SCI (Sentential Calculus with Identity, see [5,7]), its extension with the laws of Boolean algebra, WB, modal logic S0.5 [3] and an extension of S0.5 recently proposed by Mateusz Klonowski (results unpublished).
The relations between non-Fregean logics WT, WH (both are strengthenings of WB) and modal logics S4, S5 were established already by Suszko (see [6]). Modal counterparts of some modifications of SCI were examined by T. Ishii [1,2]. However, modal counterparts of SCI and WB have not been described in the literature of the subject.
Based on the Kripke-style semantics for S0.5 developed by Andrzej Pietruszczak [4], I will present an extension of this semantics for all the four mentioned logics. Some results concerning the idea o af modal logic being the counterpart of a non-Fregea logic will be discussed together with its issues. In addition, tableau systems for all the considered logics will be presented.
[1] T. Ishii, Propositional calculus with identity, Bulletin of the Section of Logic, 27(3):96–104.
[2] T. Ishii, Nonclassical logics with identity connective and their algebraic characterization, PhD thesis, Japan Advanced Institute of Science and Technology, 2000.
[3] E.J. Lemmon, New foundations for Lewis modal systems, The Journal of Symbolic Logic, 22(2):176–186, 1957.
[4] A. Pietruszczak, Simplified Kripke style semantics for some very weak modal logics, Logic and Logical Philosophy, 18:271–296, 2009.
[5] R. Suszko, Non-Fregean logic and theories, Analele Universitatii Bucuresti, Acta Logica, 11:105–125, 1968.
[6] R. Suszko, Identity connective and modality, Studia Logica, 27(1):7–39, 1971.
[7] R. Suszko, Abolition of the Fregean axiom, in R. Parikh (Ed.), Logic Colloquium. Symposium on Logic Held at Boston, 1972–73, Springer, 1975, pp. 169–239.
Wiktor Nowicki, 28.04.2026 o godzinie 10.00 w Katedrze Logiki.
Tytuł wystąpienia: WT-identity in the Logic of Proofs
Abstrakt: The non-Fregean Logic WT corresponds to modal S4. Its identity connective is translated into a necessary equivalence. In the Logic of Proofs the S4 necessity is enriched with information about the derivation of the bound formula, this process is called a realization. Our aim is to examine the image of WT under a translation in the context of Logic of Proofs. We focus on the differences between a standard realization and one narrowed down to such theorems, and infer what it means for the computational content of WT-identity.
O seminarium i dotychczasowych wystąpieniach: https://logicacopernicana.umk.pl/