For each sufficiently large N, there exists a unary regular language L such that both L and its complement L^c are accepted by unambiguous nondeterministic automata with at most N states while the smallest deterministic automata for these two languages require a superpolynomial number of states, at least $e^{\Omega(\sqrt[3]{N\cdot\ln^{2}\!N})}$. Actually, L and L^c are accepted by nondeterministic machines sharing the same transition graph, differing only in the distribution of their final states. As a consequence, the gap between the sizes of unary unambiguous self-verifying automata and deterministic automata is also superpolynomial.
Pairs of Complementary Unary Languages with "Balanced" Nondeterministic Automata / V. Geffert, G. Pighizzini - In: LATIN 2010 : theoretical informatics : 9th Latin American Symposium, Oaxaca, Mexico, April 19-23, 2010 : proceedings / [a cura di] A. Lopez-Ortiz. - Berlin : Springer, 2010. - ISBN 9783642121999. - pp. 196-207 (( Intervento presentato al 9. convegno Latin American Symposium on Theoretical Informatics tenutosi a Oaxaca nel 2010.
Pairs of Complementary Unary Languages with "Balanced" Nondeterministic Automata
G. PighizziniUltimo
2010
Abstract
For each sufficiently large N, there exists a unary regular language L such that both L and its complement L^c are accepted by unambiguous nondeterministic automata with at most N states while the smallest deterministic automata for these two languages require a superpolynomial number of states, at least $e^{\Omega(\sqrt[3]{N\cdot\ln^{2}\!N})}$. Actually, L and L^c are accepted by nondeterministic machines sharing the same transition graph, differing only in the distribution of their final states. As a consequence, the gap between the sizes of unary unambiguous self-verifying automata and deterministic automata is also superpolynomial.Pubblicazioni consigliate
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