A topological space in which any two (distinct) points are separated by disjoint neighbourhoods (see Hausdorff axiom). Hausdorff spaces need not be regular nor a fortiori completely regular, even when they consist only of a countable set of points or have a countable base. They were first considered by F. Hausdorff in 1914, see .
|||F. Hausdorff, "Set theory" , Chelsea, reprint (1978) (Translated from German)|
|||A.V. Arkhangel'skii, V.I. Ponomarev, "Fundamentals of general topology: problems and exercises" , Reidel (1984) (Translated from Russian)|
Hausdorff space. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Hausdorff_space&oldid=18077