I’m not really keeping abreast with what’s available on elementary category theory right now — who would have thought that revising an elementary logic text would be so all-consuming? (Maybe it is one of those cheering features of, erm, mature years … you can only think about one thing at a time.)

However, since I was just about to bring the resource to the attention of our local Part III Maths students, I thought I should quickly check my category theory page here – which, if you don’t know it, links to a lot of available lecture notes, legally available books etc, not to mention my stalled *Gentle Intro to Category Theory*. So I’ve updated some links, deleted some other seemingly dead ones, and done a small amount of tidying. Do let me know about any errors and omissions and about any newly available lecture notes, etc.

Lots of fun reading if you like that kind of thing …

David MakinsonToday received an ad from World Scientific for another into to category theory, published in March 2018, that does not seem to be on your list:

Marco Grandis, Category Theory and Applications: A Textbook for Beginners

See: https://www.worldscientific.com/worldscibooks/10.1142/10737?utm_medium=email&utm_source=to_replace&utm_campaign=to_replace

Peter SmithThanks for the pointer to this recent book, new to me! Looks interesting. Unfortunately, as far as I can see, even from within the university domain, only the first introductory chapter is freely available online, so I can’t add it to the list of books which

arefreely accessible.Rowsety MoidWorld Scientific is one of the worst offenders when it comes to overly expensive books.

Category Theory and ApplicationsisA Textbook for Beginnerswho have £86 to spare.(A point in its favour is that the Kindle edition is — somewhat unusually — far less expensive: £22.89)

Still, from a quick look, it seems interesting and reasonably well written. It also seems relatively free of category theory ideology. (For instance, it seems happy to use “standard set theory”, plus Grothendieck universes, as its “foundational setting”, without trying to undermine set theory in the reader’s mind or to make it seem fundamentally misguided.)

Peter SmithThr price is pretty outrageous, and bizarre given the apparent intended readership. I downloaded the Kindle preview, but the ugly treatment of symbols makes it (predictably) horrible to look at.