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Porosity of 𝓢-approximately continuous functions

  • Gertruda Ivanova and Renata Wiertelak
Published/Copyright: January 13, 2020
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Abstract

Considering the natural topology or 𝓢-density topology on the domain and on the range we obtain different families of continuous functions f : ℝ → ℝ. In this paper we compare these families in porosity terms. In particular, we obtain strengthening of some recent results by J. Hejduk, A. Loranty, R. Wiertelak.

MSC 2010: 54C08; 26A15; 54A10; 54C30; 54C35
  1. Communicated by Tomasz Natkaniec

References

[1] Bruckner, A. M.: Differentiation of Real Functions. Lecture Notes in Math. 659, Springer Verlag, Berlin, 1978.10.1007/BFb0069821Search in Google Scholar

[2] Filipczak, M.—Hejduk, J.: On topologies associated with the Lebesgue measure, Tatra Mt. Math. Publ. 28 (2004), 187–197.Search in Google Scholar

[3] Filipczak, M.—Ivanova, G.—Wódka, J.: Comparison of some families of real functions in porosity terms, Math. Slovaca 67 (2017), 1155–1164.10.1515/ms-2017-0039Search in Google Scholar

[4] Foran, J.: Continuous functions need not have σ-porous grphs, Real Anal. Exchange 11(5) (1985–86), 194–203.10.2307/44151739Search in Google Scholar

[5] Haupt, O.—Pauc, C.: La topologie de Denjoy approximative envisagée comme vraie topologie, C. R. Acad. Sci. Paris 234 (1952), 390–392.Search in Google Scholar

[6] Hejduk, J.—Loranty, A.—Wiertelak, R.: On 𝓙-continuous functions, Tatra Mt. Math. Publ. 65 (2016), 49–59.10.1515/tmmp-2016-0004Search in Google Scholar

[7] Hejduk, J.—Wiertelak, R.: On the abstract density topologies generated by lower and almost lower density operators, Traditional and Present-day Topics in Real Analysis, Łodź University Press, 2013.10.18778/7525-971-1.25Search in Google Scholar

[8] Hejduk, J.—Wiertelak, R.: On the generalization of density topologies on the real line, Math. Slovaca 64(5) (2014), 1267–1276.10.2478/s12175-014-0274-ySearch in Google Scholar

[9] Ivanova, G.—Karasińska, A.—Wagner-Bojakowska, E.: Comparison of some subfamilies of functions having the Baire property, Tatra Mt. Math. Publ. 65 (2016), 151–159.10.1515/tmmp-2016-0013Search in Google Scholar

[10] Ivanova, G.—Wagner-Bojakowska, E.: On some modification of Darboux property, Math. Slovaca 66(1) (2016), 79–88.10.1515/ms-2015-0117Search in Google Scholar

[11] Ivanova, G.—Wagner-Bojakowska, E.: On some modification of Świátkowski property, Tatra Mt. Math. Publ. 58 (2014), 101–109.Search in Google Scholar

[12] Ivanova, G.—Wagner-Bojakowska, E.: On some subclasses of the family of Darboux Baire 1 functions, Opuscula Math. 34(4) (2014), 777–788.10.7494/OpMath.2014.34.4.777Search in Google Scholar

[13] Ivanova, G.—Wagner-Bojakowska, E.: On some subfamilies of Darboux quasi-continuous functions Bull. Soc. Sci. Lett. Łódź Sér. Rech. Déform. 64(3) (2014), 31–43.Search in Google Scholar

[14] Ivanova, G.—Wagner-Bojakowska, E.: Porous subsets in the space of functions having the Baire property, Math. Slovaca 67(6) (2017), 1333–1344.10.1515/ms-2017-0055Search in Google Scholar

[15] Kowalczyk, S.—Turowska, M.: Methods of comparison of families in porosity terms, Georgian Math. J., 10.1515/gmj-2019-2025.Search in Google Scholar

[16] Strobin, F.—Wiertelak, R.: Algebrability of 𝓢-continuous functions, Topology Appl. 231 (2017), 373–385.10.1016/j.topol.2017.09.021Search in Google Scholar

[17] Strobin, F.—Wiertelak, R.: On a generalization of density topologies on the real line, Topology Appl. 199 (2016), 1–16.10.1016/j.topol.2015.11.005Search in Google Scholar

[18] Wiertelak, R.: On 𝓢-approximately continuous functions, submitted.10.1007/s10998-011-7071-ySearch in Google Scholar

[19] Zajiček, L.: On σ-porous sets in abstract spaces, Abstr. Appl. Anal. 5 (2005), 509–534.10.1155/AAA.2005.509Search in Google Scholar

[20] Zajiček, L.: Porosity and σ-porosity, Real Anal. Exchange 13 (1987–88), 314–350.10.2307/44151885Search in Google Scholar

Received: 2019-03-02
Accepted: 2017-07-12
Published Online: 2020-01-13
Published in Print: 2020-02-25

© 2020 Mathematical Institute Slovak Academy of Sciences

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