Abstract
Answering a question of E. K. van Douwen and W. F. Pfeffer [1], we prove that the countable power of the Sorgenfrey line is a D-space. To establish this result we use a method of proof which we call reverse induction. This method allows to establish certain properties of a product \(\prod_{{i}=0}^{\infty}{X}_{i}\) by making a kind of ``reverse induction step'' from \(\prod_{{i}={n}+1}^{\infty}{X}_{i} {\rm to} \prod_{{i}={n}}^{\infty}{X}_{i}\) for an arbitrary natural n.
Similar content being viewed by others
References
Dennis K. Burke, Covering properties, in: Handbook of Set-theoretic Topology, North- Holland (Amsterdam, 1984), pp. 347–422.
Peter de Caux, Yet another property of the Sorgenfrey plane, Topology Proc., 6 (1981), 31–43.
Eric K. van Douwen and Washek F. Pfeffer, Some properties of the Sorgenfrey line and related spaces, Pacific J. Math., 81 (1979), 371–377.
Todd Eisworth, On D-spaces, in: Open Problems in Topology. II, Elsevier B.V. (Amsterdam, 2007), pp. 129–134.
Gary Gruenhage, A survey of D-spaces, in: Set Theory and its Applications, Contemp. Math., vol. 533, Amer. Math. Soc. (Providence, RI, 2011), pp. 13–28.
Klaas Pieter Hart, Jun-iti Nagata, and Jerry E. Vaughan (eds.), Encyclopedia of General Topology, Elsevier Science Publishers, B.V. (Amsterdam, 2004).
Kenneth Kunen, Set Theory, Studies in Logic (London), vol. 34, College Publications (London, 2011).
David J. Lutzer, Another property of the Sorgenfrey line, Compos. Math., 24 (1972), 359–363.
Author information
Authors and Affiliations
Corresponding author
Additional information
The work was performed as part of research conducted in the Ural Mathematical Center with the financial support of the Ministry of Education and Science of the Russian Federation (Agreement number 075-02-2021-1383).
Rights and permissions
About this article
Cite this article
Patrakeev, M. Reverse induction proof of D property of the countable power of the Sorgenfrey line. Acta Math. Hungar. 165, 112–133 (2021). https://doi.org/10.1007/s10474-021-01169-z
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10474-021-01169-z