Abstract
We prove an effective characterization of languages having dot-depth 3/2. Let B 3/2 denote this class, i.e., languages that can be written as finite unions of languages of the form u 0 L 1 u 1 L 2 u 2 ...L n u n, where u i ∈ A* and L i are languages of dot-depth one. Let F be a deterministic finite automaton accepting some language L. Resulting from a detailed study of the structure of B 3/2, we identify a pattern P (cf. Fig. 2) such that L belongs to B 3/2 if and only if F does not have pattern P in its transition graph. This yields an NL-algorithm for the membership problem for B 3/2.
Due to known relations between the dot-depth hierarchy and symbolic logic, the decidability of the class of languages definable by Σ 2-formulas of the logic FO[<, min, max, S, P] follows. We give an algebraic interpretation of our result.
Supported by the Studienstiftung des Deutschen Volkes.
Supported by the Deutsche Forschungsgemeinschaft (DFG), grant Wa 847/4-1.
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References
M. Arfi. Opérations polynomiales et hiérarchies de concaténation. Theoretical Computer Science, 91:71–84, 1991.
J. A. Brzozowski and R. Knast. The dot-depth hierarchy of star-free languages is infinite. Journal of Computer and System Sciences, 16:37–55, 1978.
J. A. Brzozowski. Hierarchies of aperiodic languages. RAIRO Inform. Theor., 10:33–49, 1976.
R. S. Cohen and J. A. Brzozowski. Dot-depth of star-free events. Journal of Computer and System Sciences, 5:1–16, 1971.
C. Choffrut and J. Karhumäki. Combinatorics of words. In G. Rozenberg and A. Salomaa, editors, Handbook of formal languages, volume I, pages 329–438. Springer, 1996.
C. Glaßer. A normalform for classes of concatenation hierarchies. Technical Report 216, Inst. für Informatik, Univ. Würzburg, 1998.
C. Glaßer and H. Schmitz. Languages of dot-depth 3/2. Technical Report 243, Inst. für Informatik, Univ. Würzburg, 1999.
K. Hashiguchi. Representation theorems on regular languages. Journal of Computer and System Sciences, 27:101–115, 1983.
G. Higman. Ordering by divisibility in abstract algebras. In Proc. London Math. Soc., volume 3, pages 326–336, 1952.
R. Knast. A semigroup characterization of dot-depth one languages. RAIRO Inform. Théor., 17:321–330, 1983.
R. McNaughton and S. Papert. Counterfree Automata. MIT Press, Cambridge, 1971.
J. E. Pin. A variety theorem without complementation. Russian Math., 39:74–83, 1995.
J. E. Pin. Syntactic semigroups. In G. Rozenberg and A. Salomaa, editors, Handbook of formal languages, volume I, pages 679–746. Springer, 1996.
D. Perrin and J. E. Pin. First-order logic and star-free sets. Journal of Computer and System Sciences, 32:393–406, 1986.
J. E. Pin and P. Weil. Polynomial closure and unambiguous product. Theory. of computing systems, 30:383–422, 1997.
I. Simon. Hierarchies of events with dot-depth one. PhD thesis, University of Waterloo, 1972.
I. Simon. Factorization forests of finite height. Theoretical Computer Science, 72:65–94, 1990.
J. Sakarovitch and I. Simon. Subwords. In M. Lothaire, editor, Combinatorics on Words, Encyclopedia of mathematics and its applications, pages 105–142. Addison-Wesley, 1983.
J. Stern. Characterizations of some classes of regular events. Theoretical Computer Science, 35:17–42, 1985.
H. Straubing. A generalization of the Schützenberger product of finite monoids. Theoretical Computer Science, 13:137–150, 1981.
H. Straubing. Finite semigroups varieties of the form V * D. J. Pure Appl. Algebra, 36:53–94, 1985.
H. Straubing. Semigroups and languages of dot-depth two. Theoretical Computer Science, 58:361–378, 1988.
D. Thérien. Classification of finite monoids: the language approach. Theoretical Computer Science, 14:195–208, 1981.
W. Thomas. Classifying regular events in symbolic logic. Journal of Computer and System Sciences, 25:360–376, 1982.
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Glaßer, C., Schmitz, H. (2000). Languages of Dot-Depth 3/2. In: Reichel, H., Tison, S. (eds) STACS 2000. STACS 2000. Lecture Notes in Computer Science, vol 1770. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-46541-3_46
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DOI: https://doi.org/10.1007/3-540-46541-3_46
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