Article
Keywords:
convergence space; cardinal function; inequality; set-theoretic topology
Summary:
We extend the Noble and Ulmer theorem and the Juhász and Hajnal theorems in set-theoretic topology. We show that a statement analogous to that in the former theorem is valid for a family of almost topological convergences, whereas statements analogous to those in the latter theorems hold for a pretopologically Hausdorff convergence.
References:
[1] Alexandroff, P. S., Urysohn, P. S.:
Über kompakte topologische Räume. Akad. Nauk SSSR, Trudy Mat. Inst. Steklov 31 (1950), 94 pages Russian.
MR 0043445 |
Zbl 0041.31504
[2] Čech, E.:
Topological Spaces. Publishing House of the Czechoslovak Academy of Sciences, Prague; John Wiley & Sons, London (1966).
MR 0211373 |
Zbl 0141.39401
[3] Choquet, G.:
Convergences. Ann. Univ. Grenoble, Sect. Sci. Math. Phys., II. Ser. 23 (1948), 57-112.
MR 0025716 |
Zbl 0031.28101
[8] Reynolds, J. P.:
Hausdorff closedness in the convergence setting. Topol. Proc. 49 (2017), 135-152.
MR 3546386 |
Zbl 1373.54006