Last-modified: 2010-09-01 (水) 22:11:19
Let X be a topological space and let A be its subspace with the induced topology. For any A-closed set K and X-open cover U of the X-closure of K, there exists a finite subcover V of U such that the A-closures of the members of V cover X.
D. E. Cameron, Some maximal topologies which are QHC, Proc. Amer. Math. Soc. Vol.75, No.1 (1979).