Last-modified: 2011-05-29 (日) 14:50:31
- Let (X,τ) be a topological space. X is said to be weakly R_0 , briefly w-R_0 , if .
- A topological space (X,τ) is weakly-R_0 iff for each x in X, ker(x) ≠ X.
- If a space X is w-R_0, then for every topological space Y, the product space X×Y is also w-R_0.
- If a product X×Y is w-R_0, the at least one of the factor is w-R_0.
- weakly R_0 ⇒ weakly semi-R_0. 
- Di Maio, Giuseppe, A separation axiom weaker than R0., (English) [J] Indian J. Pure Appl. Math. 16, 373-375 (1985).
- Arya, S.P.; Nour, T.M., Weakly semi-R_0 spaces., (English) [J] Indian J. Pure Appl. Math. 21, No.12, 1083-1085 (1990).