Organizatorzy

prof. dr hab. Mikołaj Bojańczyk
prof. dr hab. Damian Niwiński

Informacje

środy, 14:15 , sala: 5440

Dziedziny badań

Lista referatów

18 listopada 2020 14:15
Janusz Schmude (MIM UW)
Polynomial grammars with substitution
Polynomial grammars are grammars whose nonterminals generate tuples of integers (or elements of some ring in general) and productions use polynomial functions. They proved to be useful for proving decidability of equivalence of MSO transductions …
4 listopada 2020 14:15
Mikołaj Bojańczyk (MIM UW)
Regular expressions for data words
I will discuss a proposal (one of many others) for regular expressions that use infinite alphabets. The regular expressions describe exactly the languages that can be recognised by nondeterministic orbit-finite automata (equivalently, nondeterministic register automata). …
21 października 2020 14:15
Szymon Toruńczyk (Uniwersytet Warszawski (MIMUW))
A model-theoretic characterization of bounded twin-width
Twin-width is a graph parameter introduced recently in a series of papers by Bonnet, Geniet, Kim, Thomassé, and Watrigant. Among others, classes of bounded twin-width include all proper minor-closed classes, all classes of bounded tree-width …
14 października 2020 14:00
Colin Geniet (ENS Paris-Saclay)
Twin-Width of Graphs
Twin-width is a graph complexity measure based on a notion of width of permutations by Guillemot and Marx [SODA '14]. Twin-width is defined through sequences of d-contractions, which witness that the twin-width is at most …
24 czerwca 2020 14:15
Pierre Pradic (ENS Lyon)
Implicit automata in λ-calculi (joint work with Lê Thành Dũng)
This work is part of an exploration of the expressiveness of the simply-typed λ-calculus (STLC) and related substructural variants (linear, affine, planar) using Church encodings of datatypes. More specifically, we are interested in the connection …
17 czerwca 2020 14:15
Jakub Gajarsky (Uniwersytet Warszawski)
Differential games for FO logic
I will introduce differential games for FO logic of graphs, a new variant of Ehrenfeucht-Fraisse games. These games are an attempt to extend currently used locality-based techniques for FO logic in a way which works …
10 czerwca 2020 14:15
Nathanael Fijalkow (CNRS, LaBRI)
Learning Probabilistic Context-Free Grammar
In this talk I will report on a joint work with Alexander Clark about learning (a subclass of) probabilistic context-free grammars published in the Transactions of the Association for Computational Linguistics. The objective of the …
3 czerwca 2020 14:15
Julian Salamanca (Uniwersytet Warszawski)
Lattices do not distribute over powerset
I will show that there is no distributive law of the free lattice monad over the powerset monad. The proof presented also works for other classes of lattices such as (bounded) distributive/modular lattices and also …
27 maja 2020 14:15
Joost Winter
From automata theory to coinduction with Haskell
In this talk I will approach a topic from classical automata theory, power series in a single input variable, from the point of view of coinductive specifications in the functional language Haskell, which are easy …
20 maja 2020 14:15
Vincent Michielini (Uniwersytet Warszawski)
Regular choices and uniformisations for countable domains (joint work with Michał Skrzypczak)
Considering the following question: given (in a sense which will be clarified in the talk) a countable totally ordered set D, on which condition(s) does there exist a choice function over D (i.e. a function …
13 maja 2020 14:15
Denis Kuperberg (CNRS, LIP, ENS Lyon)
Computational content of circular proof systems (joint work with Laureline Pinault and Damien Pous)
Cyclic proofs are a class of formal proof systems that allow some kind of circular reasoning. Unlike classical proofs, represented by finite trees with axioms as leaves, cyclic proofs are represented by trees containing infinite …
6 maja 2020 14:15
Filip Mazowiecki (MPI SWS)
The monitoring problem for timed automata (joint work with Alejandro Grez, Michał Pilipczuk, Gabriele Puppis and Cristian Riveros)
We study a variant of the classical membership problem in automata theory, which consists of deciding whether a given input word is accepted by a given automaton. We do so under a different perspective, that …
29 kwietnia 2020 14:15
Mikołaj Bojańczyk (Uniwersytet Warszawski)
Single use transducers over infinite alphabets (joint work with Rafał Stefański)
Automata for infinite alphabets, despite the undeniable appeal, are a bit of a theoretical mess. Almost all models are non-equivalent as language recognisers: deterministic/nondeterministic/alternating, one-way/two-way, etc. Also monoids give a different class of languages, and …
22 kwietnia 2020 14:15
Wojciech Czerwiński (Uniwersytet Warszawski)
Universality problem for unambiguous Vector Addition Systems with States (joint work with Diego Figueira and Piotr Hofman)
I will show that the universality problem is ExpSpace-complete for unambiguous VASS, which is in strong contrast with Ackermann-completeness of the same problem for nondeterministic VASS. I also plan to present some more results concerning …
15 kwietnia 2020 14:15
Bartek Klin (Uniwersytet Warszawski)
Monadic MSO logic
The correspondence of regular languages and monadic second-order logic relies on the fact that the class of regular languages is closed under images of surjective letter-to-letter homomorphisms. This closure property holds for finite words, but …