Abstract
We study the properties of syntactic monoids of bifix-free regular languages. In particular, we solve an open problem concerning syntactic complexity: We prove that the cardinality of the syntactic semigroup of a bifix-free language with state complexity n is at most \((n-1)^{n-3}+(n-2)^{n-3}+(n-3)2^{n-3}\) for \(n \geqslant 6\). The main proof uses a large construction with the method of injective function. Since this bound is known to be reachable, and the values for \(n \leqslant 5\) are known, this completely settles the problem. We also prove that \((n-2)^{n-3} + (n-3)2^{n-3} - 1\) is the minimal size of the alphabet required to meet the bound for \(n \geqslant 6\). Finally, we show that the largest transition semigroups of minimal DFAs which recognize bifix-free languages are unique up to renaming the states.
M. Szykuła—Supported in part by the National Science Centre, Poland under project number 2014/15/B/ST6/00615.
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References
Berstel, J., Perrin, D., Reutenauer, C.: Codes and Automata. Cambridge University Press, Cambridge (2009)
Brzozowski, J.A.: Quotient complexity of regular languages. J. Autom. Lang. Comb. 15(1/2), 71–89 (2010)
Brzozowski, J.A.: In search of the most complex regular languages. Int. J. Found. Comput. Sci. 24(6), 691–708 (2013)
Brzozowski, J.A., Li, B.: Syntactic complexity of \(R\)- and \(J\)-trivial languages. Int. J. Found. Comput. Sci. 16(3), 547–563 (2005)
Brzozowski, J.A., Li, B., Liu, D.: Syntactic complexities of six classes of star-free languages. J. Autom. Lang. Comb. 17, 83–105 (2012)
Brzozowski, J.A., Li, B., Ye, Y.: Syntactic complexity of prefix-suffix-, bifix-, and factor-free regular languages. Theoret. Comput. Sci. 449, 37–53 (2012)
Brzozowski, J., Szykuła, M.: Upper bounds on syntactic complexity of left and two-sided ideals. In: Shur, A.M., Volkov, M.V. (eds.) DLT 2014. LNCS, vol. 8633, pp. 13–24. Springer, Cham (2014). doi:10.1007/978-3-319-09698-8_2
Brzozowski, J.A., Szykuła, M.: Large aperiodic semigroups. Int. J. Found. Comput. Sci. 26(07), 913–931 (2015)
Brzozowski, J., Szykuła, M.: Upper bound on syntactic complexity of suffix-free languages. In: Shallit, J., Okhotin, A. (eds.) DCFS 2015. LNCS, vol. 9118, pp. 33–45. Springer, Cham (2015). doi:10.1007/978-3-319-19225-3_3
Brzozowski, J.A., Tamm, H.: Theory of átomata. Theoret. Comput. Sci. 539, 13–27 (2014)
Brzozowski, J., Ye, Y.: Syntactic complexity of ideal and closed languages. In: Mauri, G., Leporati, A. (eds.) DLT 2011. LNCS, vol. 6795, pp. 117–128. Springer, Heidelberg (2011). doi:10.1007/978-3-642-22321-1_11
Ferens, R., Szykuła, M.: Complexity of bifix-free languages. In: Carayol, A., Nicaud, C. (eds.) CIAA 2017. LNCS, vol. 10329, pp. 76–88. Springer, Cham (2017)
Holzer, M., König, B.: On deterministic finite automata and syntactic monoid size. Theoret. Comput. Sci. 327, 319–347 (2004)
Iván, S., Nagy-György, J.: On nonpermutational transformation semigroups with an application to syntactic complexity (2014). http://arxiv.org/abs/1402.7289
McNaughton, R., Papert, S.A.: Counter-free automata (M.I.T. Research Monograph No. 65). The MIT Press (1971)
Myhill, J.: Finite automata and representation of events. Wright Air Development Center Technical report, pp. 57–624 (1957)
Pin, J.E.: Syntactic semigroups. In: Rozenberg, G., Salomaa, A. (eds.) Handbook of Formal Languages, Volume 1 Word, Language, Grammar, pp. 679–746. Springer, Heidelberg (1997)
Szykuła, M., Wittnebel, J.: Syntactic complexity of bifix-free languages (2017). http://arxiv.org/abs/1604.06936
Yu, S.: State complexity of regular languages. J. Autom. Lang. Comb. 6, 221–234 (2001)
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Szykuła, M., Wittnebel, J. (2017). Syntactic Complexity of Bifix-Free Languages. In: Carayol, A., Nicaud, C. (eds) Implementation and Application of Automata. CIAA 2017. Lecture Notes in Computer Science(), vol 10329. Springer, Cham. https://doi.org/10.1007/978-3-319-60134-2_17
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