Category Theory for Scientists (2018) [pdf]

arxiv.org

82 points·adenadel··9 comments

A thread from 2015: https://news.ycombinator.com/item?id=9651828

Am I missing something or the last X -> X' on Example 2.1.2.3 is inverted? Shouldn't it be X' -> X?

New version (2018): https://arxiv.org/pdf/1302.6946v1.pdf

The linked version is from 2013.

Nope, that's an older version than http://math.mit.edu/~dspivak/CT4S.pdf . The date you see under the title is the date when the file was last compiled (which is done automatically by arXiv every once in a while), because arXiv is still too stupid to redefine \today when compiling files. The date in grey on the left margin of page 1 is the right one.

The proper new version has been published by MIT press in 2014 and can be downloaded from the usual places where books can be downloaded.

I believe this was the version I originally posted.

The best way to ensure access to the newest arXiv version is not to link to a specific version at all (and also link to the abstract): https://arxiv.org/abs/1302.6946 . EDIT: But, for no comprehensible reason, Spivak has things set up so that the latest arXiv version is older (although I don't understand why a file updated February 2013 is dated April 2018 …); so just ignore me. Sorry!

HN's software rewrites arxiv.org URLs to the base page for that reason. But in this case, replacing a 2013 pdf with a 2018 pdf requires the more specific document link.

Good point; it's exceedingly weird that the version uploaded February 2013 is dated April 2018 (on the file itself), whereas the most recent version, dated later in 2013, has a date printed on the file that's also in 2013 ….

Ok, we've changed to that from http://math.mit.edu/~dspivak/CT4S.pdf. Thanks!

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