Published online by Cambridge University Press: 20 November 2018
In his paper ″Indexed systems of neighborhoods for general topological spaces″ (Amer. Math. Monthly 68, (1961), 886–893), A.S. Davis defined a hierarchy of what he called regularity axioms. The R1 -axiom is independent of both T0 and T1, but is strictly weaker than T2. In this note, we propose to study the properties of the spaces satisfying the R1 -axiom. In particular, we will show that in many well-known results, the hypothesis can be weakened from T2 to R1, which is part of our motivation in studying R1 -spaces.
Research partially supported by the Summer Research Institute of the Canadian Mathematical Congress.
1 Research partially supported by the Summer Research Institute of the Canadian Mathematical Congress.