A note on metrics and tolerances
A note on monotone countable paracompactness
We show that a space is MCP (monotone countable paracompact) if and only if it has property , introduced by Teng, Xia and Lin. The relationship between MCP and stratifiability is highlighted by a similar characterization of stratifiability. Using this result, we prove that MCP is preserved by both countably biquotient closed and peripherally countably compact closed mappings, from which it follows that both strongly Fréchet spaces and q-space closed images of MCP spaces are MCP. Some results on...
A note on multivalued Baire category theorem
A note on operators extending partial ultrametrics
We consider the question of simultaneous extension of partial ultrametrics, i.e. continuous ultrametrics defined on nonempty closed subsets of a compact zero-dimensional metrizable space. The main result states that there exists a continuous extension operator that preserves the maximum operation. This extension can also be chosen so that it preserves the Assouad dimension.
A note on pairwise c-compact bitopological spaces
A note on products of Fréchet spaces
A note on Raghavan-Reilly's pairwise paracompactness.
A note on sequence-covering -images of metric spaces
A note on some fixed point results.
A note on -spaces and -metrizable spaces
In this paper, we give the mapping theorems on -spaces and -metrizable spaces by means of some sequence-covering mappings, mssc-mappings and -mappings.
A note on star Lindelöf, first countable and normal spaces
A topological space is said to be star Lindelöf if for any open cover of there is a Lindelöf subspace such that . The “extent” of is the supremum of the cardinalities of closed discrete subsets of . We prove that under every star Lindelöf, first countable and normal space must have countable extent. We also obtain an example under , which shows that a star Lindelöf, first countable and normal space may not have countable extent.
A note on the comparison of topologies.
A note on the Hurewicz isomorphism theorem in Borsuk's theory of shape
A note on the invariance of Baire spaces under mappings
A note on the non-emptiness of the limit of approximate systems
Short proofs of the fact that the limit space of a non-gauged approximate system of non-empty compact uniform spaces is non-empty and of two related results are given.
A note on topological groups and their remainders
In this note we first give a summary that on property of a remainder of a non-locally compact topological group in a compactification makes the remainder and the topological group all separable and metrizable. If a non-locally compact topological group has a compactification such that the remainder of belongs to , then and are separable and metrizable, where is a class of spaces which satisfies the following conditions: (1) if , then every compact subset of the space is a...
A note on topological model theory
A Note on Totally Bounded Quasi-Uniformities
We present the original proof, based on the Doitchinov completion, that a totally bounded quiet quasi-uniformity is a uniformity. The proof was obtained about ten years ago, but never published. In the mean-time several stronger results have been obtained by more direct arguments [8, 9, 10]. In particular it follows from Künzi’s [8] proofs that each totally bounded locally quiet quasi-uniform space is uniform, and recently Déak [10] observed that even each totally bounded Cauchy quasi-uniformity...
A note on weakly hereditarily closure-preserving families.
A note on -universal spaces