Abstract
We answer questions of Arhangel’skiĭ using spaces defined from combinatorial objects. We first establish further convergence properties of a space constructed from ✷(κ) showing it is Fréchet-Urysohn for finite sets and a w-space that is not a W-space. We also show that under additional assumptions it may be not bi-sequential, and so providing a consistent example of an absolutely Fréchet α1 space that is not bise-quential. In addition, if we do not require the space being α1, we can construct a ZFC example of a countable absolutely Fréchet space that is not bisequential from an almost disjoint family of subsets of the natural numbers.
| Original language | English |
|---|---|
| Pages (from-to) | 379-389 |
| Number of pages | 11 |
| Journal | Applied General Topology |
| Volume | 24 |
| Issue number | 2 |
| DOIs | |
| State | Published - 2 Oct 2023 |
| Externally published | Yes |
Keywords
- Fréchet-Urysohn
- W-space
- bi-sequential
- w-space
- α-space
ASJC Scopus subject areas
- Geometry and Topology
Fingerprint
Dive into the research topics of 'Strong Fréchet properties of spaces constructed from squares and AD families'. Together they form a unique fingerprint.Cite this
- APA
- Author
- BIBTEX
- Harvard
- Standard
- RIS
- Vancouver