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1. • CommentRowNumber1.
   • CommentAuthorTim_Porter
   • CommentTimeSep 28th 2013
   • (edited Sep 28th 2013)
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   Author: Tim_Porter
   Format: MarkdownItexThere was already a discussion of ends in the topological sense at [[proper homotopy]]. (I had never seen the term hemicompact before. I knew of $\sigma$-compact which is almost the same.)

   There was already a discussion of ends in the topological sense at proper homotopy. (I had never seen the term hemicompact before. I knew of $\sigma$-compact which is almost the same.)

2. • CommentRowNumber2.
   • CommentAuthorTobyBartels
   • CommentTimeSep 28th 2013
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   Author: TobyBartels
   Format: MarkdownItexYes, I wrote [[end compactification]] based off of Wikipedia. I still want to convince myself that this is all self-consistent.

   Yes, I wrote end compactification based off of Wikipedia. I still want to convince myself that this is all self-consistent.

3. • CommentRowNumber3.
   • CommentAuthorTobyBartels
   • CommentTimeSep 28th 2013
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   Author: TobyBartels
   Format: MarkdownItexAt [[proper homotopy theory]], the definition uses the closures of compact subspaces rather than the compact subspaces themselves. It does seem to be a little easier to define the concept using these. Are there examples to show why one way is better than the other? Or are they secretly equivalent?

   At proper homotopy theory, the definition uses the closures of compact subspaces rather than the compact subspaces themselves. It does seem to be a little easier to define the concept using these. Are there examples to show why one way is better than the other? Or are they secretly equivalent?

4. • CommentRowNumber4.
   • CommentAuthorTim_Porter
   • CommentTimeSep 28th 2013
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   Author: Tim_Porter
   Format: MarkdownItexI quote from Wikipedia Every hemicompact space is σ-compact. The converse, however, is not true; for example, the space of rationals, with the usual topology, is σ-compact but not hemicompact.

   I quote from Wikipedia

   Every hemicompact space is σ-compact. The converse, however, is not true; for example, the space of rationals, with the usual topology, is σ-compact but not hemicompact.

5. • CommentRowNumber5.
   • CommentAuthorTobyBartels
   • CommentTimeSep 29th 2013
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   Author: TobyBartels
   Format: MarkdownItexYes, I noticed that. I don\'t know if that was in answer to my question >Are there examples to show why one way is better than the other? Or are they secretly equivalent? but that\'s not what I was asking about. I was asking about using compact subpsaces versus the closures of compact subspaces in the definition of ‘end’.

   Yes, I noticed that. I don't know if that was in answer to my question

   Are there examples to show why one way is better than the other? Or are they secretly equivalent?

   but that's not what I was asking about.

   I was asking about using compact subpsaces versus the closures of compact subspaces in the definition of ‘end’.