alt.hn

7/3/2026 at 8:42:00 PM

Applied Category Theory Course (2018)

https://math.ucr.edu/home/baez/act_course/index.html

by measurablefunc

7/3/2026 at 11:32:47 PM

As a programmer interested in category theory, I found this book a rather good balance between the abstract non-sense of CT and what I might actually use in programming. I wonder if anyone else has good books to recommend? I feel that the contents of the book remains a bit hard to appreciate in full unless you have ran into these concepts previously.

by Jhsto

7/4/2026 at 12:41:35 AM

F. William Lawvere - Conceptual Mathematics: A First Introduction to Categories

Eugenia Cheng - The Joy of Abstraction: An Exploration of Math, Category Theory, and Life

She builds up to the category theory chapters.

Book club: https://youtube.com/playlist?list=PLhgq-BqyZ7i7tEEQVG5rlOG8y...

by 363849473754

7/4/2026 at 10:49:05 AM

Thanks for the links! The first book seems very good (I already own the latter).

by Jhsto

7/4/2026 at 11:18:29 AM

For a more advanced book: Category Theory in Context by Emily Riehl

by 363849473754

7/4/2026 at 9:00:25 AM

Not sure of your level, but as a beginner, these two were recommended to me on HN previously:

- https://www.cambridge.org/highereducation/books/conceptual-m...

- https://bartoszmilewski.com/2014/11/04/category-the-essence-... (a blog series on CT specifically for programmers)

by jhartikainen

7/4/2026 at 10:59:09 AM

Kiitos! My level is graduate, but part of the challenge with category theory is that some of the terms are quite unsuggestive. I feel that after seeing enough examples, I can start making more sense what some concept would be in Finnish, which helps me remember what was what and what it might relate to.

Edit: Also realized you're in Oulu, feel free to email me if you'd be up to meeting in-person to discuss these further!

by Jhsto

7/4/2026 at 5:17:15 PM

The part in the beginning about Galois Connections is very worth learning. It has countless applications.

by ufo

7/3/2026 at 10:46:35 PM

Yay, John!

by not_a_bot_4sho

7/4/2026 at 4:21:18 PM

I participated there and couldn't guess for the life of me how does Baez gathers the amount of energy needed to put together all the materials, setup all the exercises and review and comment all the participation in a tuition free everybody-welcomed online experience such as that, beyond his normal academic duties. In the link there are the e-lectures but all the online forum give-and-take is sadly lost.

by jesuslop

7/3/2026 at 11:51:03 PM

I knew it was going to be Baez just from the title and domain.

by esafak

7/4/2026 at 1:29:19 AM

John Baez' recent work on Mathematics of Tuning Systems is such a fun read. I enjoy how he explains ideas so clearly that the general public can understand and appreciate.

by lioeters

7/3/2026 at 11:06:25 PM

Applied category theory, like abstract mathematics, lol?

by pishpash

7/3/2026 at 11:26:34 PM

thats an oxymoron

by semiinfinitely