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Well, I'm trying to prove the following exercise:

Let $X$ be a compact Hausdorff space and its cardinality is greater than the real numbers. Then $X$ is Lindelöf but not separable.

Could someone try to give an idea how to handle this problem? Thanks. :)

Bohrer
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1 Answers1

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That $X$ is Lindelof is trivial since every compact Hausdorff space is by definition also Lindelof. So the interesting part is to prove that the cardinality of $X$ is at most the cardinality of the reals.

The second part is false, there is a compact Hausdorff space of cardinality $2^{ |\Bbb R|}$ that is separable, namely the Stone-Cech compactification of the natural numbers. See Question about the cardinality of a space

See also,e.g. Theorem 3.6.12 and 3.6.14 in Richard Engelking, General Topololy (1989).

Hint. I could not think of the answer immediately, but I found the above answer when I googled:
cardinality compact Hausdorff separable space

Mirko
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