Title
Variable automata over infinite alphabets
Abstract
Automated reasoning about systems with infinite domains requires an extension of regular automata to infinite alphabets. Existing formalisms of such automata cope with the infiniteness of the alphabet by adding to the automaton a set of registers or pebbles, or by attributing the alphabet by labels from an auxiliary finite alphabet that is read by an intermediate transducer. These formalisms involve a complicated mechanism on top of the transition function of automata over finite alphabets and are therefore difficult to understand and to work with. We introduce and study variable finite automata over infinite alphabets (VFA). VFA form a natural and simple extension of regular (and ω-regular) automata, in which the alphabet consists of letters as well as variables that range over the infinite alphabet domain. Thus, VFAs have the same structure as regular automata, only that some of the transitions are labeled by variables. We compare VFA with existing formalisms, and study their closure properties and classical decision problems. We consider the settings of both finite and infinite words. In addition, we identify and study the deterministic fragment of VFA. We show that while this fragment is sufficiently strong to express many interesting properties, it is closed under union, intersection, and complementation, and its nonemptiness and containment problems are decidable. Finally, we describe a determinization process for a determinizable subset of VFA.
Year
DOI
Venue
2010
10.1007/978-3-642-13089-2_47
LATA
Keywords
Field
DocType
infinite word,variable automaton,variable finite automaton,infinite alphabet domain,infinite alphabet,vfa form,regular automaton,deterministic fragment,finite alphabet,auxiliary finite alphabet,infinite domain,finite automata,decision problem,automated reasoning
Discrete mathematics,Quantum finite automata,Combinatorics,Automata theory,Nondeterministic finite automaton,Computer science,Closure (mathematics),Automaton,Decidability,Finite-state machine,ω-automaton
Conference
Volume
ISSN
ISBN
6031
0302-9743
3-642-13088-7
Citations 
PageRank 
References 
43
1.21
13
Authors
3
Name
Order
Citations
PageRank
Orna Grumberg14361351.99
Orna Kupferman23548223.79
Sarai Sheinvald3585.19