Abstract
We study the descriptional complexity of the k-th power and positive closure operations on the classes of prefix-, suffix-, factor-, and subword-free, -closed, and -convex regular languages, and on the classes of right, left, two-sided, and all-sided ideal languages. We show that the upper bound kn on the nondeterministic complexity of the k-th power in the class of regular languages is tight for closed and convex classes, while in the remaining classes, the tight upper bound is \(k(n-1)+1\). Next we show that the upper bound n on the nondeterministic complexity of the positive closure operation in the class of regular languages is tight in all considered classes except for classes of factor-closed and subword-closed languages, where the complexity is one. All our worst-case examples are described over a unary or binary alphabet, except for witnesses for the k-th power on subword-closed and subword-convex languages which are described over a ternary alphabet. Moreover, whenever a binary alphabet is used for describing a worst-case example, it is optimal in the sense that the corresponding upper bounds cannot be met by a language over a unary alphabet. The most interesting result is the description of a binary factor-closed language meeting the upper bound kn for the k-th power. To get this result, we use a method which enables us to avoid tedious descriptions of fooling sets. We also provide some results concerning the deterministic state complexity of these two operations on the classes of free, ideal, and closed languages.
Research supported by VEGA grant 2/0132/19 and grant APVV-15-0091.
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References
Birget, J.: Intersection and union of regular languages and state complexity. Inf. Process. Lett. 43(4), 185–190 (1992). https://doi.org/10.1016/0020-0190(92)90198-5
Brzozowski, J., Jirásková, G., Li, B., Smith, J.: Quotient complexity of bifix-, factor-, and subword-free regular languages. Acta Cybernet. 21(4), 507–527 (2014). https://doi.org/10.14232/actacyb.21.4.2014.1
Brzozowski, J.A., Jirásková, G., Li, B.: Quotient complexity of ideal languages. Theor. Comput. Sci. 470, 36–52 (2013). https://doi.org/10.1016/j.tcs.2012.10.055
Brzozowski, J.A., Jirásková, G., Zou, C.: Quotient complexity of closed languages. Theory Comput. Syst. 54(2), 277–292 (2014). https://doi.org/10.1007/s00224-013-9515-7
Brzozowski, J.A., Sinnamon, C.: Complexity of left-ideal, suffix-closed and suffix-free regular languages. In: Drewes, F., Martín-Vide, C., Truthe, B. (eds.) LATA 2017. LNCS, vol. 10168, pp. 171–182. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-53733-7_12
Čevorová, K.: Square on ideal, closed and free languages. In: Shallit and Okhotin [27], pp. 70–80. https://doi.org/10.1007/978-3-319-19225-3_6
Čevorová, K.: Square on closed languages. In: Bordihn, H., Freund, R., Nagy, B., Vaszil, G. (eds.) NCMA 2016. books@ocg.at, vol. 321, pp. 121–130. Österreichische Computer Gesellschaft (2016)
Čevorová, K., Jirásková, G., Mlynárčik, P., Palmovský, M., Šebej, J.: Operations on automata with all states final. In: Ésik, Z., Fülöp, Z. (eds.) Proceedings of 14th International Conference on Automata and Formal Languages, AFL 2014. EPTCS, vol. 151, pp. 201–215 (2014). https://doi.org/10.4204/EPTCS.151.14
Cmorik, R., Jirásková, G.: Basic operations on binary suffix-free languages. In: Kotásek, Z., Bouda, J., Černá, I., Sekanina, L., Vojnar, T., Antoš, D. (eds.) MEMICS 2011. LNCS, vol. 7119, pp. 94–102. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-25929-6_9
Domaratzki, M., Okhotin, A.: State complexity of power. Theor. Comput. Sci. 410(24–25), 2377–2392 (2009). https://doi.org/10.1016/j.tcs.2009.02.025
Han, Y., Salomaa, K.: Nondeterministic state complexity for suffix-free regular languages. In: McQuillan and Pighizzini [24], pp. 189–196. https://doi.org/10.4204/EPTCS.31.21
Han, Y., Salomaa, K., Wood, D.: Nondeterministic state complexity of basic operations for prefix-free regular languages. Fund. Inform. 90(1–2), 93–106 (2009). https://doi.org/10.3233/FI-2009-0008
Holzer, M., Kutrib, M.: Nondeterministic descriptional complexity of regular languages. Int. J. Found. Comput. Sci. 14(6), 1087–1102 (2003). https://doi.org/10.1142/S0129054103002199
Hopcroft, J.E., Ullman, J.D.: Introduction to Automata Theory, Languages and Computation. Addison-Wesley, Reading (1979)
Hospodár, M., Jirásková, G., Mlynárčik, P.: Nondeterministic complexity of operations on closed and ideal languages. In: Han, Y.-S., Salomaa, K. (eds.) CIAA 2016. LNCS, vol. 9705, pp. 125–137. Springer, Cham (2016). https://doi.org/10.1007/978-3-319-40946-7_11
Hospodár, M., Jirásková, G., Mlynárčik, P.: Nondeterministic complexity of operations on free and convex languages. In: Carayol, A., Nicaud, C. (eds.) CIAA 2017. LNCS, vol. 10329, pp. 138–150. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-60134-2_12
Hospodár, M., Jirásková, G., Mlynárčik, P.: A survey on fooling sets as effective tools for lower bounds on nondeterministic complexity. In: Böckenhauer, H.-J., Komm, D., Unger, W. (eds.) Adventures Between Lower Bounds and Higher Altitudes. LNCS, vol. 11011, pp. 17–32. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-98355-4_2
Hospodár, M., Jirásková, G., Mlynárčik, P.: Nondeterministic complexity in subclasses of convex languages. Theor. Comput. Sci. (2019). https://doi.org/10.1016/j.tcs.2018.12.027
Jirásková, G.: State complexity of some operations on binary regular languages. Theor. Comput. Sci. 330(2), 287–298 (2005). https://doi.org/10.1016/j.tcs.2004.04.011
Jirásková, G., Krausová, M.: Complexity in prefix-free regular languages. In: McQuillan and Pighizzini [27], pp. 197–204. https://doi.org/10.4204/EPTCS.31.22
Jirásková, G., Mlynárčik, P.: Complement on prefix-free, suffix-free, and non-returning NFA languages. In: Jürgensen, H., Karhumäki, J., Okhotin, A. (eds.) DCFS 2014. LNCS, vol. 8614, pp. 222–233. Springer, Cham (2014). https://doi.org/10.1007/978-3-319-09704-6_20
Jirásková, G., Olejár, P.: State complexity of intersection and union of suffix-free languages and descriptional complexity. In: Bordihn, H., Freund, R., Holzer, M., Kutrib, M., Otto, F. (eds.) NCMA 2009. books@ocg.at, vol. 256, pp. 151–166. Österreichische Computer Gesellschaft (2009)
Jirásková, G., Palmovský, M., Šebej, J.: Kleene closure on regular and prefix-free languages. In: Holzer, M., Kutrib, M. (eds.) CIAA 2014. LNCS, vol. 8587, pp. 226–237. Springer, Cham (2014). https://doi.org/10.1007/978-3-319-08846-4_17
McQuillan, I., Pighizzini, G. (eds.): DCFS 2010, EPTCS, vol. 31 (2010). https://doi.org/10.4204/EPTCS.31
Mlynárčik, P.: Complement on free and ideal languages. In: Shallit and Okhotin [27], pp. 185–196. https://doi.org/10.1007/978-3-319-19225-3_16
Rampersad, N.: The state complexity of \({L}^2\) and \({L}^k\). Inf. Process. Lett. 98(6), 231–234 (2006). https://doi.org/10.1016/j.ipl.2005.06.011
Shallit, J., Okhotin, A. (eds.): DCFS 2015. LNCS, vol. 9118. Springer, Cham (2015). https://doi.org/10.1007/978-3-319-19225-3
Sinnamon, C.: Complexity of proper suffix-convex regular languages. In: Câmpeanu, C. (ed.) CIAA 2018. LNCS, vol. 10977, pp. 324–338. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-94812-6_27
Sipser, M.: Introduction to the Theory of Computation. Cengage Learning, Boston (2012)
Yu, S.: Regular languages. In: Rozenberg, G., Salomaa, A. (eds.) Handbook of Formal Languages, vol. 1, pp. 41–110. Springer, Heidelberg (1997). https://doi.org/10.1007/978-3-642-59136-5_2
Yu, S., Zhuang, Q., Salomaa, K.: The state complexities of some basic operations on regular languages. Theor. Comput. Sci. 125(2), 315–328 (1994). https://doi.org/10.1016/0304-3975(92)00011-F
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Hospodár, M. (2019). Descriptional Complexity of Power and Positive Closure on Convex Languages. In: Hospodár, M., Jirásková, G. (eds) Implementation and Application of Automata. CIAA 2019. Lecture Notes in Computer Science(), vol 11601. Springer, Cham. https://doi.org/10.1007/978-3-030-23679-3_13
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