Organizers

dr hab. Aleksy Schubert, prof. ucz.
prof. dr hab. Andrzej Tarlecki
prof. dr hab. Paweł Urzyczyn

Information

Fridays, 12:15 p.m. , room: 5450

Research fields

List of talks

May 9, 2025, 12:15 p.m.
Michał Gajda
The constructive negation and postintuitionism (Konstruktywna negacja i postintuicjonizm)
I will attempt at a minimalist exposure of ultrafinitist logic with quantifiers (both forall and exists), which is expansion of previous work published in https://drops.dagstuhl.de/enti<wbr></wbr>ties/document/10.4230/LIPIcs.<wbr></wbr>TYPES.2023.5. Beside quantifiers, I also add equality and show how to …
April 25, 2025, 12:15 p.m.
Michał Gajda (MIMUW)
On foundations of mathematics (O podstawach matematyki)
April 11, 2025, 12:15 p.m.
Aleksy Schubert (MIMUW)
Inhabitation in System F with simple instantiations (Inhabitacja w Systemie F z prostym instancjonowaniem)
We consider the fragment of System F where universal quantifiers may occur only on negative positions and propositional variables may only be instantiated by simple types. The inhabitation problem for this fragment is proved to …
March 28, 2025, 12:15 p.m.
Konrad Zdanowski (UKSW)
Not all Kripke models of HA are locally PA, part II (Nie wszystkie modele arytmetyki Heytinga spełniają lokalnie artytmetykę Peano, część II)
I will present the results of Erfan Khaniki's work, Not All Kripke Models of HA Are Locally PA, from 2022. In this paper, the author provides a negative solution to a long-standing open problem: whether …
March 21, 2025, 12:15 p.m.
Konrad Zdanowski (UKSW)
Not all Kripke models of HA are locally PA, part I (Nie wszystkie modele arytmetyki Heytinga spełniają lokalnie artytmetykę Peano, część I)
I will present the results of Erfan Khaniki's work, Not All Kripke Models of HA Are Locally PA, from 2022. In this paper, the author provides a negative solution to a long-standing open problem: whether …
March 14, 2025, 12:15 p.m.
Mikołaj Konarski
Formal Mathematical Reasoning: A New Frontier in AI (Formalne rozumowanie matematyczne – nowy front w badaniach AI)
The revolution in machine learning applications has also reached research on the formalization of mathematics. In this talk, I will present an overview of contemporary achievements in this field.
Dec. 13, 2024, 12:15 p.m.
Jan Kostrzon (MIMUW)
Relevant S is undecidable (Nierozstrzygalność relewantnej logiki S)
I will present an article of Søren Knudstorp `Relevant S is undecidable' from LICS'24. The talk will start with a definition of semilattice models, then the lack of the finite model property will be shown …
Dec. 6, 2024, 12:15 p.m.
Aleksy Schubert (MIMUW)
Higher-order matching, unfolding and recapitulation (Dopasowanie wyższego rzędu, rozwijanie i podsumowanie)
The third transformation in Stirling's proof of the higher-order matching decidability is called unfolding. I will present its definition and I will sketch the final recapitulation of the Stirling's proof. Notably, the transformation is defined …
Nov. 29, 2024, 12:15 p.m.
Aleksy Schubert (MIMUW)
Higher-order matching, transformations T1 and T2 and 4th order matching (Dopasowanie wyższego rzędu, transformacje T1 i T2 oraz dopasowanie czwartego rzędu)
Stirling's proof of the higher-order matching decidability uses two basic solution transformations called T1 and T2 and then the third transformation called unfolding. The vocabulary introduced on the previous talk will make it easy to …
Oct. 18, 2024, 12:15 p.m.
Aleksy Schubert (MIMUW)
Stirling games in the proof of the higher-order matching problem decidability (Gry Stirlinga w dowodzie rozstrzygalności problemu dopasowania wyższego rzędu)
The initial part of the Stirling's proof that the higher order matching problem is decidable is devoted to the notion of specific game. This game approach is simply a framework in which a reduction machine …
Oct. 11, 2024, 12:15 p.m.
Aleksy Schubert (MIM)
The context of the higher-order matching problem (Kontekst problemu dopasowania wyższego rzędu)
The higher-order matching problem is a notoriously difficult decision problem, which was solved by Colin Stirling positively. However, the existing proof is very difficult to understand. I will present the basic definitions concerning the problem …
May 17, 2024, 12:15 p.m.
Konrad Zdanowski (UKSW)
A simplified lower bound for implicational logic (Uproszczona dolna granica dla logiki implikacyjnej)
A streamlined and simplified exponential lower bound on the length of proofs in intuitionistic implicational logic will be presented. The construction suffices to be adaptated to Gordeev and Haeusler’s dag-like natural deduction.
April 5, 2024, 12:15 p.m.
Michał Walicki (University of Bergen)
Paradoxes and truth in a logic of sentential operators (Paradoksy i prawda w logice operacji zdaniowych)
We show how to extend any classical (first or higher order) language with the sentential quantifiers and operators. Graph-based semantics coincides with the classical one for the classical sublanguage. The self-referential capabilities allow to express …
June 16, 2023, 12:15 p.m.
Maciej Zielenkiewicz (MIM)
Small model property in games and automata
Small model property is an important property that implies decidability. We show that the small model size is directly related to some important resources in games and automata for checking provability.
June 2, 2023, 12:15 p.m.
Aleksy Schubert (MIM)
O nierozstrzygalności wyprowadzania typów przy ograniczonej randze lub arności
W modelowaniu języków funkcyjnych z polimorfizmem ważną rolę odgrywa System F Girarda i Reynoldsa. Wiadomo, że dla termów w stylu Curry'ego, jeśli system nie jest w żaden sposób ograniczony, to wyprowadzanie typów jest nierozstrzygalne już …