Last-modified: 2011-04-16 (土) 14:59:22
- Let (X,τ) be a topological space and Y be a closed discrete? collectioin of points of X. The collction Y is said to be screened if it can be simultaneously separated by disjoint open set.
- Willam G. Fleissner, On λ collection Hausdorff spaces, Topology Proceedings 2, (1977, 445-456.