Basic Category Theory · HackerPapers discussions

Basic Category Theory — mentioned by seanhunter

Sat, 18 Apr 2026 11:10:43 GMT

If you want to learn category theory in a way that is more orthodox, a lot of people recommend Tom Leinster’s Basic Category Theory, which is free[1]. I’m going to be working through it soon, but the bit I’ve skimmed through looks really good if more “mathsy” than things like TFA. It also does a better job (imo) of justifying the existence of category theory as a field of study. [1] https://arxiv.org/pdf/1612.09375

Paper and discussion history. A mention is not an endorsement.

Basic Category Theory — HN submission

Tue, 18 Jun 2024 01:58:43 GMT

Basic Category Theory (2016)

2 points; 0 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Basic Category Theory — mentioned by bmacho

Wed, 19 Oct 2022 20:15:42 GMT

> And actually.. since a vector space has an underlying set, it seems to me that to do a direct sum on a vector space, you must first do a direct sum on the set (that is, do a disjoint union), and then do other things to map the rest of the structure of a vector space into the sum. No. > So, somehow, a disjoint union (of the underlying set) becomes a cartesian product (of the whole vector space)? No. If anything it is the other way: the cartesian product of the underlying sets becomes the (equivalent of) "disjoint union" of the vector spaces. > (Is there somewhere to read about this to gain…

Paper and discussion history. A mention is not an endorsement.

Basic Category Theory — mentioned by stablenode

Tue, 18 Aug 2020 15:39:02 GMT

feanaro: fine, if you think so. I find it interesting that actual mathematicians working in Category Theory, such as Tom Leinster (who wrote a lovely little introductory text on Category Theory [not covering monads though] and made it freely available on arXiv: https://arxiv.org/abs/1612.09375) are able to engage in polite discussion about the contentious viewpoints on the use of CT without resorting to personal attacks (see 2-3 minutes from his talk from a few years back: https://youtu.be/UoutGluNVlI?t=410) ... which stands in sharp contrast to some of the evangelists, whose attitude in…

Paper and discussion history. A mention is not an endorsement.

Basic Category Theory — mentioned by autopoiesis

Thu, 22 Aug 2019 19:47:49 GMT

It sounds like you would be interested in the book / course '7 Sketches in Compositionality' by David Spivak and Brendan Fong, which studies precisely those ideas categorically, with a particular focus on systems that you might broadly call 'computational': http://math.mit.edu/~dspivak/teaching/sp18/ It has been discussed on Hacker News at least a couple of times previously -- fairly recently, even. You might be interested to look at these discussions: https://news.ycombinator.com/item?id=20376325 https://news.ycombinator.com/item?id=19701767 Edit to add: You might also be interested to learn…

Paper and discussion history. A mention is not an endorsement.

Basic Category Theory — HN submission

Tue, 03 Jan 2017 09:31:14 GMT

Basic Category Theory (textbook)

2 points; 3 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Basic Category Theory — HN submission

Mon, 02 Jan 2017 23:40:52 GMT

Basic Category Theory

248 points; 85 discussion replies on HN. Paper and source history. A submission is not an endorsement.

Basic Category Theory — HN submission

Mon, 02 Jan 2017 20:54:13 GMT

[1612.09375] Basic Category Theory [pdf]

6 points; 3 discussion replies on HN. Paper and source history. A submission is not an endorsement.