Organizatorzy

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

Informacje

środy, 14:15 , sala: 5050

Dziedziny badań

Lista referatów

20 grudnia 2006 14:15
Sławomir Lasota (Uniwersytet Warszawski)
Bisimulation equivalence and commutative context-free grammars
The topic will be the class of processes (transition systems) generated from the commutative context-free grammars. I will present a method enabling to prove decidability (and to compute the complexity) of different variants of bisimulation …
29 listopada 2006 14:15
Mikołaj Bojańczyk (Uniwersytet Warszawski)
Two-way temporal logic over unranked trees
I will talk about languages of unranked trees that can be defined in a temporal logic with two operators: exists some ancestor, and exists some descendant. The point is to have an algorithm, which decides …
23 listopada 2006 14:15
Marcin Jurdziński (Uniwersytet Warszawski)
Subexponential algorithms for solving parity games
Solving parity games is polynomial time equivalent to the modal mu-calculus model checking problem and its exact computational complexity is an intriguing open problem: it is known to be in UP (unambiguous NP) and co-UP, …
15 listopada 2006 14:15
Filip Murlak (Uniwersytet Warszawski)
Weak automata and Wadge hierarchy
I will show a new lower bound for the height of the Wadge hierarchy of weak tree languages, i. e., the languages of infinite trees recognizable with weak automata. To this end I will prove …
25 października 2006 14:15
Jacek Jurewicz (Uniwersytet Warszawski)
Panic automata
Panic automata are an extension of second-order pushdown automata (that operate on a second-order pushdown store, ie. a stack of stacks) by the destructive "panic" operation introduced by P. Urzyczyn in order to fully relate …
11 października 2006 14:15
Eryk Kopczynski (Uniwersytet Warszawski)
Half-positionally determined winning conditions
Basic definitions: games, half-positional determinacy. - Half-positional winning conditions and omega-regular languages. How to check whether the given omega-regular winning condition is finitely half-positional? - Positional/suspendable conditions (PS). Definitions and examples. Half-positional determinacy of a …
4 października 2006 14:15
Henrik Bjorklund (Dortmund)
Toward Regular Data Languages
7 czerwca 2006 14:15
Sibylle Froeschle
The computational dichotomy of true-concurrency
In concurrency theory there is a divide between the interleaving approach, in which concurrency is reduced to nondeterministic sequentialization, and the truly-concurrent approach, which represents concurrency in a more faithful way. In this talk I …
31 maja 2006 14:15
Piotr Hoffman (Uniwersytet Warszawski)
Word problems
The talk will be an introduction to the world of word problems, in particular word problems for varieties of semigroups. Attention will be paid especially to commutative semigroups (reversible Petri nets). I intend to prove …
24 maja 2006 14:15
Michał Strojnowski (Uniwersytet Warszawski)
Impossibility Proofs for Distributed Computing
Many problems have no solution in distributed computing. One of the best known examples is Byzantine Generals Problem, for which it is shown that if at least one third of the generals are malicious, there …
10 maja 2006 14:15
Slawomir Lasota (joint work with Wojciech Rytter) (Uniwersytet Warszawski)
On language and bisimulation equivalence of context-free processes
In contrast to language equivalence, being undecidable for (normed) context-free grammars, the bisimulation equivalence is decidable; and it is even polynomial for normed grammars.The fastest known algorithm for checking bisimulation equivalence worked in $O(n^{13})$ time. …
26 kwietnia 2006 14:15
Linh Anh Nguyen (joint work with Rajeev Gore) (Uniwersytet Warszawski)
Tableaux for Regular Grammar Logics of Agents Using Automaton-Modal Formulae
A grammar logic is a multimodal logic extending Kn with inclusion axioms of the form [t1]...[th]j (r) [s1]...[sk]j where t1, ..., th, s1, ..., sk are modal indices. Such an axiom can be seen as …
29 marca 2006 14:15
Mikolaj Bojanczyk (Uniwersytet Warszawski)
Reachability in vector-addition systems
An (n-dimensional) vector addition system is a finite set V of n-dimensional integer vectors. The reachability problem is as follows: given V and two n-dimensional vectors of *naturals * v and w, determine if one …
22 marca 2006 14:15
Piotr Hoffman (Uniwersytet Warszawski)
Word problems in sums of monoids
In the talk I will investigate the decidability of word problems for amalgams (sums) of monoids. Word problems for amalgams of monoids are equivalent to sums of congruence relations on words. They are also equivalent …
15 marca 2006 14:15
Hugo Gimbert
Positional Stochastic Strategies
We present ongoing work on positionality of full-information, two-player, zero-sum stochastic games with finitely many states.