# Talk:Heine-Borel Theorem/Real Line

I believe, by doing a little research, that the initial statement is wrong. It should be made to apply only to a closed real interval, not a general closed set in $\R$. Comments? --prime mover 03:46, 16 March 2012 (EDT)
Somehow, I do think that the theorem statement is true. I think that it is just that the proof doesn't prove the general case for a closed subspace of $\R^n$.
By the Heine-Borel Theorem/Metric Space, we have that a subset of $\R^n$ is compact if and only if it is complete and totally bounded (if my proof is valid).
Then we have that $\R^n$ is complete.
So a subspace of $\R^n$ is closed if and only if it is complete.
It is quite easy to show that a subspace of $\R^n$ is bounded if and only if it is totally bounded.
So we get the Heine-Borel Theorem/Euclidean Space, which states that a subspace of $\R^n$ is compact if and only if it is closed and bounded.