Re: No homeomorphism (0,1) <--> [0,1]



On 08-09-2005 17:34, Michael Stemper wrote:

I'm trying to prove that there isn't a homeomorphism between [0,1]
and (0,1), and I'm stuck. What I know so far is the definitions of
homeomorphism and continuity.

Suppose that there was a homeomorphism f:[0,1] --> ]0,1[. It's continuous, and so, by Weierstrass' theorem, it has a maximum and a minimum; let's call them M and m respectively. You know that m and M belong to ]0,1[ and that f([0,1]) is a subset of [m,M]. Therefore, f is not surjective.

Best regards,

Jose Carlos Santos
.



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