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Keywords:
Aull-paracompactness of $Y$ in $X$; strong star-normality of $Y$ in $X$
Summary:
We prove for a subspace $Y$ of a $T_1$-space $X$, $Y$ is (strictly) Aull-paracompact in $X$ and $Y$ is Hausdorff in $X$ if and only if $Y$ is strongly star-normal in $X$. This result provides affirmative answers to questions of A.V. Arhangel'skii–I.Ju. Gordienko [3] and of A.V. Arhangel'skii [2].
References:
[1] Arhangel'skii A.V.: Relative topological properties and relative topological spaces. Topology Appl. 70 (1996), 87-99. MR 1397067 | Zbl 0848.54016
[2] Arhangel'skii A.V.: From classic topological invariants to relative topological properties. Sci. Math. Japon. 55 (2002), 153-201. MR 1885790
[3] Arhangel'skii A.V., Gordienko I.Ju.: Relative symmetrizability and metrizability. Comment. Math. Univ. Carolinae 37 (1996), 757-774. MR 1440706 | Zbl 0886.54001
[4] Burke D.K.: Covering properties. in: K. Kunen, J.E. Vaughan (eds.), Handbook of Set-Theoretic Topology, North-Holland, Amsterdam, 1984, pp.347-422. MR 0776628 | Zbl 0569.54022
[5] Engelking R.: General Topology. Heldermann Verlag, Berlin, 1989. MR 1039321 | Zbl 0684.54001
[6] Hoshina T., Yamazaki K.: Weak $C$-embedding and $P$-embedding, and product spaces. Topology Appl. 125 (2002), 233-247. MR 1933574 | Zbl 1013.54006
[7] Yamazaki K.: Absolute weak $C$-embedding in Hausdorff spaces. Topology Appl. 131 (2003), 273-279. MR 1983083 | Zbl 1025.54010
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