Cotygodniowe seminarium badawcze
Organizatorzy
- prof. dr hab. Mikołaj Bojańczyk
- prof. dr hab. Damian Niwiński
Informacje
środy, 14:15 , sala: 5440Dziedziny badań
Lista referatów
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28 maja 2014 14:15
Szczepan Hummel (Uniwersytet Warszawski)
Unambiguity-preserving operations on tree languages that lift topological complexity
The talk reports my results concerning lower bound for the topological complexity of the class of languages of infinite trees recognized by unambiguous automata.At the beginning I will show operation sigma that has the following …
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21 maja 2014 14:15
Tomasz Gogacz (Uniwersytet Wrocławski)
All instances termination of chase is undecidable
We show that all instances termination of chase is undecidable.More precisely, there is no algorithm deciding, for a given set Tconsisting of Tuple Generating Dependencies (a.k.a. Datalog+/- program), whether the T-chase on D will terminate …
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14 maja 2014 14:15
Wojciech Czerwiński (Uniwersytet Warszawski)
Deciding branching bisimilarity on BPA in NEXPTIME (joint work with Petr Jancar)
Branching bisimilarity is a variant of the weak bisimilarity. Recently there was a big progress in deciding bisimilarity on context-free systems: decidability was shown. I will present the main ideas of this result and explain …
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7 maja 2014 14:15
Paweł Parys (Uniwersytet Warszawski)
How Many Numbers Can a Lambda-term Contain?
It is well known, that simply-typed lambda-terms can be used to represent numbers, as well as some other data types, in particular tuples of numbers. We prove, however, that in a lambda-term of a fixed …
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23 kwietnia 2014 14:15
Mikołaj Bojańczyk (Uniwersytet Warszawski)
Star height via games
I will show a simplified proof of decidability for the star height problem. The simplified proof follows the same lines as the proof of Daniel Kirsten: first the star height problem is reduced to the …
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16 kwietnia 2014 14:15
Michał Skrzypczak (Uniwersytet Warszawski)
Kolmogorov's R-sets and regular tree languages
R-sets, introduced in 1928 by Andrey Kolmogorov, were designed as a wide class of well-behaved sets that can be described in a constructible way. One of the crucial properties of this class is universal measurability …
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9 kwietnia 2014 14:15
Michał Skrzypczak (Uniwersytet Warszawski)
Determinisation of History Deterministic Automata
A non-deterministic automaton is history deterministic if it is possible to resolve its choices in a way that depends only on the already read input. Such automata appear naturally in synthesis problems and qualitative models.One …
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2 kwietnia 2014 14:15
Szymon Toruńczyk (Uniwersytet Warszawski)
Turing Machine with Atoms and Descriptive Complexity
We relate Turing Machines with Atoms to a certain logic over finite structures. As an application to Descriptive Complexity Theory, within a substantial class of relational structures including Cai-Fürer-Immerman graphs, we precisely characterize those subclasses …
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26 marca 2014 14:15
Luc Dartois (LIAFA, Paris)
Adding Modular predicates
When considering classes of regular languages, it is a primordial question to be able to determine if a given language belongs to it. Over fragments of logic, this question has been largely studied since McNaughton-Papert …
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25 marca 2014 14:15
Olivier Serre (LIAFA, Paris)
Playing with Automata and Trees
Roughly speaking a finite automaton on infinite trees is a finite memory machine that takes as input an infinite node-labelled binary tree and processes it in a top-down fashion as follows. It starts at the …
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19 marca 2014 14:15
Nathanaël Fijalkow (Uniwersytet Warszawski)
The value 1 problem for probabilistic automata
I will talk about probabilistic automata, which are automata assigning to each word a probability to be accepted. Specifically, I will be interested in the value 1 problem, which asks whether for a given probabilistic …
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12 marca 2014 14:15
Joanna Ochremiak (Uniwersytet Warszawski)
Turing Machines with Atoms and Constraint Satisfaction Problems (joint work with Bartek Klin, Sławomir Lasota, Szymon Toruńczyk) - continuatio)
We study deterministic computability over sets with atoms. We characterize those alphabets for which Turing machines with atoms determinize. To this end, the determinization problem is expressed as a Constraint Satisfaction Problem, and a characterization …
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5 marca 2014 14:15
Joanna Ochremiak (Uniwersytet Warszawski)
Turing Machines with Atoms and Constraint Satisfaction Problems (joint work with Bartek Klin, Sławomir Lasota, Szymon Toruńczyk)
We study deterministic computability over sets with atoms. We characterize those alphabets for which Turing machines with atoms determinize. To this end, the determinization problem is expressed as a Constraint Satisfaction Problem, and a characterization …
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26 lutego 2014 14:15
Mikołaj Bojańczyk (Uniwersytet Warszawski)
Transducers with origin information
Call a string-to-string transducer regular if it can be realised by one of the following equivalent models: mso transductions, two-way deterministic automata with output, and streaming transducers with registers. In the talk, I will propose …