Title
Index problems for game automata
Abstract
For a given regular language of infinite trees, one can ask about the minimal number of priorities needed to recognize this language with a nondeterministic, alternating, or weak alternating parity automaton. These questions are known as, respectively, the nondeterministic, alternating, and weak Rabin-Mostowski index problems. Whether they can be answered effectively is a long-standing open problem, solved so far only for languages recognizable by deterministic automata (the alternating variant trivializes). We investigate a wider class of regular languages, recognizable by so-called game automata, which can be seen as the closure of deterministic ones under complementation and composition. Game automata are known to recognize languages arbitrarily high in the alternating Rabin-Mostowski index hierarchy; that is, the alternating index problem does not trivialize anymore. Our main contribution is that all three index problems are decidable for languages recognizable by game automata. Additionally, we show that it is decidable whether a given regular language can be recognized by a game automaton.
Year
DOI
Venue
2015
10.1145/2946800
ACM Transactions on Computational Logic (TOCL)
Keywords
Field
DocType
Automata over infinite trees,alternation,parity games,Rabin-Mostowski index
Discrete mathematics,Quantum finite automata,Two-way deterministic finite automaton,Automata theory,Combinatorics,Deterministic automaton,Nondeterministic finite automaton,Nested word,Deterministic finite automaton,Mathematics,ω-automaton
Journal
Volume
Issue
ISSN
17
4
1529-3785
Citations 
PageRank 
References 
0
0.34
18
Authors
3
Name
Order
Citations
PageRank
Alessandro Facchini1359.47
Filip Murlak218419.14
Michal Skrzypczak32311.34