TY - GEN

T1 - An infinite automaton characterization of double exponential time

AU - La Torre, Salvatore

AU - Madhusudan, P.

AU - Parlato, Gennaro

PY - 2008/12/25

Y1 - 2008/12/25

N2 - Infinite-state automata are a new invention: they are automata that have an infinite number of states represented by words, transitions defined using rewriting, and with sets of initial and final states. Infinite-state automata have gained recent interest due to a remarkable result by Morvan and Stirling, which shows that automata with transitions defined using rational rewriting precisely capture context-sensitive (NLinSpace) languages. In this paper, we show that infinite automata defined using a form of multi-stack rewriting precisely defines double exponential time (more precisely, 2ETime, the class of problems solvable in time). The salient aspect of this characterization is that the automata have no ostensible limits on time nor space, and neither direction of containment with respect to 2ETime is obvious. In this sense, the result captures the complexity class qualitatively, by restricting the power of rewriting.

AB - Infinite-state automata are a new invention: they are automata that have an infinite number of states represented by words, transitions defined using rewriting, and with sets of initial and final states. Infinite-state automata have gained recent interest due to a remarkable result by Morvan and Stirling, which shows that automata with transitions defined using rational rewriting precisely capture context-sensitive (NLinSpace) languages. In this paper, we show that infinite automata defined using a form of multi-stack rewriting precisely defines double exponential time (more precisely, 2ETime, the class of problems solvable in time). The salient aspect of this characterization is that the automata have no ostensible limits on time nor space, and neither direction of containment with respect to 2ETime is obvious. In this sense, the result captures the complexity class qualitatively, by restricting the power of rewriting.

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U2 - 10.1007/978-3-540-87531-45

DO - 10.1007/978-3-540-87531-45

M3 - Conference contribution

AN - SCOPUS:57849104025

SN - 3540875301

SN - 9783540875307

T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

SP - 33

EP - 48

BT - Computer Science Logic - 22nd International Workshop, CSL 2008 - 17th Annual Conference of the EACSL, Proceedings

T2 - 22nd International Workshop on Computer Science Logic, CSL 2008, and 17th Annual Conference of the European Association for Computer Science Logic, EACSL

Y2 - 16 September 2008 through 19 September 2008

ER -