5 results
Wojciech Czerwiński ; Piotr Hofman ; SŁawomir Lasota.
This paper is about reachability analysis in a restricted subclass of multi-pushdown automata. We assume that the control states of an automaton are partially ordered, and all transitions of an automaton go downwards with respect to the order. We prove decidability of the reachability problem, and […]
Published on September 11, 2013
Mikołaj Bojańczyk ; Sławomir Lasota.
We define a new kind of automata recognizing properties of data words or data trees and prove that the automata capture all queries definable in Regular XPath. We show that the automata-theoretic approach may be applied to answer decidability and expressibility questions for XPath.
Published on February 16, 2012
Mikołaj Bojańczyk ; Bartek Klin ; Sławomir Lasota.
We study languages over infinite alphabets equipped with some structure that can be tested by recognizing automata. We develop a framework for studying such alphabets and the ensuing automata theory, where the key role is played by an automorphism group of the alphabet. In the process, we generalize […]
Published on August 15, 2014
Wojciech Czerwiński ; Sławomir Lasota.
The regular separability problem asks, for two given languages, if there exists a regular language including one of them but disjoint from the other. Our main result is decidability, and PSpace-completeness, of the regular separability problem for languages of one counter automata without zero tests […]
Published on June 11, 2019
Khadijeh Keshvardoost ; Bartek Klin ; Sławomir Lasota ; Joanna Ochremiak ; Szymon Toruńczyk.
We investigate the isomorphism problem in the setting of definable sets (equivalent to sets with atoms): given two definable relational structures, are they related by a definable isomorphism? Under mild assumptions on the underlying structure of atoms, we prove decidability of the problem. The core […]
Published on December 11, 2019