# Difference between revisions of "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)
Space of path components Incorrect statement that induced multiplication on space of path components gives a topological monoid structure; in fact it need not be continuous December 20, 2010 July 6, 2019 genuine conceptual confusion
Compact times paracompact implies paracompact General sloppiness in proof, missed some inclusion conditions June 3, 2017 Additional conditions were implicit when reading; carelessness in review
Homotopy type of connected sum depends on choice of gluing map Excluded one relation from cohomology ring description July 29, 2011 December 15, 2016 Ignored interaction term in analysis
Connected sum of two complex projective planes with opposite orientation Excluded one relation from cohomology ring description July 29, 2011 December 15, 2016 Ignored interaction term in analysis
Connected sum of two complex projective planes with same orientation Excluded one relation from cohomology ring description July 29, 2011 December 13, 2016 Ignored interaction term in analysis
Paracompact Hausdorff implies normal Used $U$ instead of $A$ at one place May 30, 2016 Didn't proofread carefully
Locally path-connected space Incorrectly said it is obtained by applying the locally operator May 30, 2016 Multiple definitions of "locally" floating around
Homotopy of spheres, homotopy of real projective space, homotopy of complex projective space Stated that some groups are $\mathbb{Z}$ when all we know is that sometimes they are infinite. April 2016 Difficult topic, basically just guesswork/poor sourcing
Hausdorffization provided incorrect definition that seemed prima facie plausible November 15, 2015 genuine knowledge gap, common confusion
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.
Path-connected implies connected Wrote "open" instead of "nonempty" December 25, 2009 December 19, 2014 Typo, didn't review the page carefully enough
Manifold mistakenly wrote "equivalent" for a bunch of conditions all of which need to be satisfied. November 2, 2014 Typo, didn't proofread.
Double mapping cylinder wrote $Y \to Z$ instead of $X \to Z$. November 2, 2007 February 11, 2014 Typo, didn't proofread.
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.