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Homework Statement
As the title suggests, I need to show that every manifold is regular.
There's probably something wrong with my proof, since I didn't use the Hausdorff condition, and the book almost explicitly states to do so.
The Attempt at a Solution
So, a m-manifold is a second-countable Hausdorff space X such that every point x in X has a neighborhood which is homeomorphic with an open subset of R^m.
Let x be in X. Let U be a neighborhood of x such that f : U --> V is a homeomorphism, and V is a subset of R^m. Since R^m is regular, for any point y in V, there exists a neighborhood V' of y such that Cl(V') is contained in V. Now, since f^-1(V')[tex]\subseteq[/tex]f^-1(Cl(V'))[tex]\subseteq[/tex]Cl(f^-1(V'))[tex]\subseteq[/tex]f^-1(V) = U, we conclude that f^-1(V') is the desired neighborhood around x. Hence X is regular.
I feel there's a bit of a misunderstanding here which is actually bugging me constantly (in a few other problems, too), so I'd like to straighten it out.