Abstract
Nondeterministic finite automata (NFA) with at most one accepting computation on every input string are known as unambiguous finite automata (UFA). This paper considers UFAs over a unary alphabet, and determines the exact number of states in DFAs needed to represent unary languages recognized by n-state UFAs: the growth rate of this function is \(e^{\Theta(\sqrt[3]{n \ln^2 n})}\). The conversion of an n-state unary NFA to a UFA requires UFAs with \(g(n)+O(n^2)=e^{\sqrt{n \ln n}(1+o(1))}\) states, where g(n) is Landau’s function. In addition, it is shown that the complement of n-state unary UFAs requires up to at least n 2 − o(1) states in an NFA, while the Kleene star requires up to exactly (n − 1)2 + 1 states.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Bach, E., Shallit, J.: Algorithmic Number Theory. MIT Press, Cambridge (1996)
Björklund, H., Martens, W.: The tractability frontier for NFA minimization. In: Aceto, L., Damgård, I., Goldberg, L.A., Halldórsson, M.M., Ingólfsdóttir, A., Walukiewicz, I. (eds.) ICALP 2008, Part II. LNCS, vol. 5126, pp. 27–38. Springer, Heidelberg (2008)
Chrobak, M.: Finite automata and unary languages. Theoretical Computer Science 47, 149–158 (1986); Errata: vol. 302(1-3), pp. 497–498 (2003)
Geffert, V., Mereghetti, C., Pighizzini, G.: Complementing two-way finite automata. Information and Computation 205(8), 1173–1187 (2007)
Holzer, M., Kutrib, M.: Nondeterministic descriptional complexity of regular languages. Intl. J. of Foundations of Computer Science 14, 1087–1102 (2003)
Hromkovič, J., Seibert, S., Karhumäki, J., Klauck, H., Schnitger, G.: Communication complexity method for measuring nondeterminism in finite automata. Information and Computation 172(2), 202–217 (2002)
Ingleton, A.W.: The rank of circulant matrices. Journal of the London Mathematical Society 31, 445–460 (1956)
Jiang, T., McDowell, E., Ravikumar, B.: The structure and complexity of minimal NFA’s over a unary alphabet. International Journal of Foundations of Computer Science 2(2), 163–182 (1991)
Landau, E.: Über die Maximalordnung der Permutationen gegebenen Grades (On the maximal order of permutations of a given degree). Archiv der Mathematik und Physik 3(5), 92–103 (1903)
Leung, H.: Separating exponentially ambiguous finite automata from polynomially ambiguous finite automata. SIAM Journal on Computing 27(4), 1073–1082 (1998)
Leung, H.: Descriptional complexity of NFA of different ambiguity. International Journal of Foundations of Computer Science 16(5), 975–984 (2005)
Lyubich, Y.: Bounds for the optimal determinization of nondeterministic autonomic automata. Sibirskii Matematicheskii Zhurnal 2, 337–355 (1964) (in Russian)
Maslov, A.N.: Estimates of the number of states of finite automata. Soviet Mathematics Doklady 11, 1373–1375 (1970)
Mera, F., Pighizzini, G.: Complementing unary nondeterministic automata. Theoretical Computer Science 330(2), 349–360 (2005)
Mereghetti, C., Pighizzini, G.: Optimal simulations between unary automata. SIAM Journal on Computing 30(6), 1976–1992 (2001)
Miller, W.: The maximum order of an element of a finite symmetric group. American Mathematical Monthly 94(6), 497–506 (1987)
Pighizzini, G., Shallit, J.: Unary language operations, state complexity and Jacobsthal’s function. Intl. J. of Foundations of Computer Sci. 13(1), 145–159 (2002)
Ramanujan, S.: A proof of Bertrand’s postulate. Journal of the Indian Mathematical Society 11, 181–182 (1919)
Schmidt, E.M.: Succinctness of Description of Context-Free, Regular and Unambiguous Languages, Ph. D. thesis, Cornell University (1978)
Sondow, J.: Ramanujan primes and Bertrand’s postulate. American Mathematical Monthly 116, 630–635 (2009)
Stearns, R.E., Hunt III, H.B.: On the equivalence and containment problems for unambiguous regular expressions, regular grammars and finite automata. SIAM Journal on Computing 14, 598–611 (1985)
Yu, S., Zhuang, Q., Salomaa, K.: The state complexity of some basic operations on regular languages. Theoretical Computer Science 125, 315–328 (1994)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2010 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Okhotin, A. (2010). Unambiguous Finite Automata over a Unary Alphabet. In: Hliněný, P., Kučera, A. (eds) Mathematical Foundations of Computer Science 2010. MFCS 2010. Lecture Notes in Computer Science, vol 6281. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-15155-2_49
Download citation
DOI: https://doi.org/10.1007/978-3-642-15155-2_49
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-15154-5
Online ISBN: 978-3-642-15155-2
eBook Packages: Computer ScienceComputer Science (R0)