T_3-open cover

Last-modified: 2011-01-20 (木) 01:55:01

Definition

  • In a topological space (X,τ) an open cover imgtex.fcgi?%5bres=100%5d%7b%5c%5b%20%5cmathcal%7bU%7d%20%5c%5d%7d%25.png of (X,τ) is T_3-open if for every set U in imgtex.fcgi?%5bres=100%5d%7b%5c%5b%20%5cmathcal%7bU%7d%20%5c%5d%7d%25.png there exist open sets V and W such that imgtex.fcgi?%5bres=100%5d%7b%5c%5b%20V%5csubset%20%5coverline%7bV%7d%5csubset%20W%5csubset%20X%5csetminus%20U%20%5c%5d%7d%25.png .

Reference

  • Przemski, M., Nearly T_i-continuous functions and some separation axioms. (Serbo-Croatian summary), Glas. Mat. Ser. III 21(41) (1986), no. 2, 431–435.