Talk:Cofibration

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Mathematics rating:	Stub Class	Mid Priority	Field: Topology
Please update this rating as the article progresses, or if the rating is inaccurate. Click to show/hide comments. Please add to or update the comments to suggest improvements to the article. Cronholm144 09:52, 23 May 2007 (UTC)

I think A must be a subset of X.

- Well then i is simply an inclusion map. It is better in my opinion to consider a mapping cylinder of A ajoined to X instead of just (X x 0) U (A x I).

In the third basic theorem, I don't think the biconditional always holds. I think A may have to be closed for the reverse direction to hold.

A is always closed. Follows from retraction or extension property. We may need Hausdorff though, but I am pretty certain we do not. —Preceding unsigned comment added by 128.12.72.244 (talk) 03:26, 2 October 2007 (UTC)

One always needs Hausdorff for something like this. —Preceding unsigned comment added by Polfbroekstraat (talk • contribs) 01:33, 2 March 2008 (UTC)