fulfils the T1-separation axiom and is regular.
A space satisfying the 
-separation axiom is said to be a T3-space.
T_3-Separation Axiom
See also
Hausdorff Axioms, Separation Axioms, T1-Separation Axiom, T3-SpaceThis entry contributed by Margherita Barile
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Cite this as:
Barile, Margherita. "T_3-Separation Axiom." From MathWorld--A Wolfram Web Resource, created by Eric W. Weisstein. https://mathworld.wolfram.com/T3-SeparationAxiom.html