Topospaces:Error log

Did you find something that looks like an error (or possible error) to you? Report the error quickly here (anonymous, does not require login, but you can optionally provide an email ID to be notified of the fix).

We have just started logging errors. On this page, you will find information about all errors that persisted on the site for more than one month on any page. Note: This applies only to errors that were not fixed by December 18, 2011. Errors fixed before then are not being logged on this page.

Page	Error description	Version where it was introduced	Version where it was corrected	Why error? Why not caught? ("I" refers to Vipul)
Homotopy of spheres, homotopy of real projective space, homotopy of complex projective space		April 2016	Stated that some groups are $\mathbb {Z}$ when all we know is that sometimes they are infinite.
Hausdorffization	provided incorrect definition that seemed prima facie plausible		November 15, 2015	genuine knowledge gap, common confusion
Weak homotopy equivalence of topological spaces	provided incorrect definition in the form of "induces isomorphisms on $\pi _{1}$ and on homology"		November 18, 2013	genuine knowledge gap, common confusion.
Double mapping cylinder	wrote $Y\to Z$ instead of $X\to Z$.	November 2, 2007	February 11, 2014	Typo, didn't proofread.
Manifold	mistakenly wrote "equivalent" for a bunch of conditions all of which need to be satisfied.		November 2, 2014	Typo, didn't proofread.
Jointly continuous map	typo: wrote that slice topology is finer than slice topology, meant it is finer than product topology	December 20, 2010	May 15, 2015	Typo, didn't proofread, and didn't revisit the page.