Prove that every regular Lindelöf space is normal

  • Thread starter radou
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  • #1
radou
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Homework Statement



So, one needs to prove that every regular Lindelöf space is normal, exactly as the title suggests.

The Attempt at a Solution



I used the following theorem:

Every regular space with a countable basis is normal.

Now, what we need to prove can be proved very similarily to the proof of the theorem above. It's Theorem 32.1., page 200, in Munkres.

What I had in mind:

The proof is exactly the same, with one variation.

Let B be a basis for X. We choose a basis element contained in V for every x in A. Now, for any x in X\A, choose a basis element containing X. This collection forms an open cover for X, and since X is Lindelöf, it has a countable subcollection. So, the subcollection of all the basis elements for the elements of A is countable. Hence, the rest of the proof is the same.

I hope it won't be a problem to open Munkres and look at the proof, since it was too long to type, so I decided to be practical.

Thanks in advance.
 

Answers and Replies

  • #2
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As usual, this is a perfect little proof :smile:
 
  • #3
radou
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OK, thanks! It was kind of obvious to use this theorem.
 

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