摘要
Some characterizations of paracompact maps are given in this note, and some equivalent statements of collectionwise normal maps are discussed. And also we show that if f : X→Y is a closed collectionwise normal map, and f^-1(y) is a semistratifiable subspace of X for any y ∈ Y, then f is a paracompact map.
Some characterizations of paracompact maps are given in this note, and some equivalent statements of collectionwise normal maps are discussed. And also we show that if f : X→Y is a closed collectionwise normal map, and f^-1(y) is a semistratifiable subspace of X for any y ∈ Y, then f is a paracompact map.
基金
The Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality.