countably 1-paracompact

Last-modified: 2011-08-08 (月) 22:19:13

Definition

A subset Y of a topological space X is said to be countably 1-paracompact if for every countable open cover U of X, there exists a collection V which satisfies:

  1. V consists of open subsets of X;
  2. V covers X;
  3. V refines U;
  4. V is locally finite at Y.

Remark

Reference

K.P.Hart, J. Nagata and J.E. Vaughan, Encyclopedia of general topology, Elsevier Science.