I'm a mathematician at UNAM in Mexico City. I work in algebraic topology, homotopy theory and higher category theory, but am interested in all sorts of math. I also enjoy computer programming as a hobby and am a big fan of the text editor Emacs.
Public Key
npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Profile Code
nprofile1qqs0de0kh3qasxr7waj5puts4h4td5xhr0e0dcukuj36wvu5ug9su8qpz4mhxue69uhhyetvv9ujuerfw36x7tnsw43q9uayw2
Show more details
Published at
2026-08-19T16:14:17Z Event JSON
{
"id": "0bb933457b3b9ce268a4f9894df0c6182071d5b9d89131d2333375c07518de2e" ,
"pubkey": "f6e5f6bc41d8187e776540f170adeab6d0d71bf2f6e396e4a3a73394e20b0e1c" ,
"created_at": 1787156057 ,
"kind": 0 ,
"tags": [
[
"proxy",
"https://mathstodon.xyz/users/oantolin",
"activitypub"
],
[
"client",
"Mostr",
"31990:6be38f8c63df7dbf84db7ec4a6e6fbbd8d19dca3b980efad18585c46f04b26f9:mostr",
"wss://relay.ditto.pub"
]
],
"content": "{\"name\":\"Omar Antolín\",\"about\":\"I'm a mathematician at UNAM in Mexico City. I work in algebraic topology, homotopy theory and higher category theory, but am interested in all sorts of math.\\n\\nI also enjoy computer programming as a hobby and am a big fan of the text editor Emacs.\",\"picture\":\"https://media.mathstodon.xyz/accounts/avatars/110/721/438/100/207/085/original/06c706aeaf1a6098.jpg\",\"nip05\":\"[email protected] \",\"fields\":[[\"Website\",\"https://www.matem.unam.mx/~omar\"],[\"GitHub\",\"https://github.com/oantolin\"]]}" ,
"sig": "88f9b11af1a96617951f564f0c5503e036721c1cceee7d0eb8192b6e7a030c9317e45c75f1fa7779a57e2f47f4c47438075fd7a87621a5b9ef48823ab7823cc6"
}
Last Notes npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…0zw6 Great! I'd definitely watch it. I think I'm doing OK writing non-impactful papers, but maybe some impact would be a nice change of pace. 😅 npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…0zw6 What about us? If you have slides, please share them. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…zxj6 Most Lisp dialects also have random access arrays. Many also have hash tables. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…qzwa Shing-Tung Yau won a Fields medal in 1982 and is also Chinese. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín I wonder if I should write a program to help me make decisions among several options that repeatedly presents me pairs of options and asks me to make a snap judgment on which I prefer, computing ELO scores along the way. After some number of rounds this might reveal my true preferences. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín I just read the transcript of @nprofile…9y77 and @nprofile…24wu's conversation with John Wiegley about his #Emacs #OrgMode setup that he uses to organize everything in his life. Wiegley is living in the future. He has over forty thousand entries spread throughout more than three thousand org files, around 28000 TODO items with about a thousand of them open. It's too much data to even look at so he has some very sophisticated ways of dealing with it. His org agenda views will surface random selections of entries for him to review; upon review with a few keystrokes he can schedule them to work or schedule them for further review in the future. He decided on a fairly strict set of conventions for how org entries should be written, including that the leading verb must be chosen from a controlled vocabulary and wrote a Haskell program to parse his org files and put them into a Postgres database which he can query. The database has vector search to find semantically similar items even if they are worded differently. He also has a local LLM backing an instance of OpenClaw that can query this database, access his org files and talk to him on Discord and Whatsapp, letting him find relevant entries from his org files by messaging the agent from his phone. It's amazing, maybe not something I'd want for myself, but definitely a fascinating read! https://sachachua.com/blog/2026/07/chatting-with-john-wiegley-about-personal-information-management-and-karthik-chikmagalur/ npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…hk95 The direction the touchpad scrolls in is called "natural". If you complain about it, somebody takes the macbook away. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Wow, this is bleak. https://blog.avas.space/llm-circus/ npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín That's true @nprofile…l2h8, but, in this particular case, my PR submitter used one of the Claude models. I do not say this to detract to your point, just for information. @nprofile…sve2 @nprofile…u5g7 npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…l2h8 @nprofile…u5g7 There are no changes to the readme, the LLM wrote a changelog entry and the commit message. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Oh, it turns out the person wrote the code: "the LLM did not write any code, it updated the README and copy-pasted my code then added whitespace, comments, and function documentation". That changes the situation, right? I can review this like any other human-written PR? @nprofile…l2h8 @nprofile…u5g7 npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…l2h8 That's exactly why I didn't report this! (Posting on mastodon is not a report, at least not when I post.) npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Ooh, got my first LLM-co"authored" pull request! Luckily, I think I can just turn it down saying GNU Emacs cannot take that contribution without getting into a personal discussion. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Huh, I just noticed two things: (1) org-protocol isn't working anymore, (2) I hardly ever use org-protocol, because it can't have broken recently since I haven't updated anything or changed the org-protocol configuration recently. Maybe I don't need org-protocol? (In which case I also don't need to fix it!) #Emacs #OrgMode npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín I learned a cool Euclidean geometry fact this week in our colloquium, in a talk by Benoît Bertrand of the University of Toulouse on joint work of his with my UNAM colleague Lucía López de Medrano. They don't think this geometry fact can be new, but also haven't been able to find a reference. The theorem is a generalization of the fact that the sum of the angles of a triangle is 180° to higher dimensions. This generalization is not that the sum of the solid angles of a tetrahedron is constant: that's not true! If you think of tetrahedra that are almost flat, that is, whose vertices are nearly coplanar, there are two types: (1) the vertices are nearly the vertices of a convex planar quadrilateral, or (2) the vertices are nearly a triangle with a point inside it. In case (1) the solid angles are close to 0; in case (2) the one at the central vertex is close to half a sphere (2π steradians), and the others are close to 0. It turns out that those are the extremes and the sum of the solid angles of a tetrahedron is always between 0 and 2π steradians. So how does their generalization go? Consider an n-dimensional simplex and select one of its vertices, say P. Now consider all ways coloring the vertices of the simplex with either red or blue in such a way that P is blue (this is half of all colorings). For each coloring look at the vectors of the form R-B where R is some red vertex and B is a blue one, and take the cone they generate (that is, the linear combinations of those vectors with non-negative coefficients). Their theorem says that those cones tile a half-space! (Here "tile" means the interiors are disjoint and the union of the cones is a half-space.) Next, a proof. 1/2 npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…3kqn Yes. More generally the square root of a positive integer is either a positive integer or it is irrational. So, for example, √30 is irrational because 5² < 30 < 6². npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…muy0 @nprofile…l2h8 I think the user wanted a manifesto promising you will maintain the status quo, which is the funniest use of the word "manifesto" I can recall. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…hk95 You might like @nprofile…nlhz's Casual menu for Calc. http://yummymelon.com/devnull/announcing-casual-an-opinionated-porcelain-for-emacs-calc.html npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…g0ws As the philosopher Neil Peart wrote: Macros within macros in a spiral array, a pattern so grand and complex, time after time we loose site of the way, our causes can't see their effects. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…l2h8 I think "more staff" is a very optimistic Freudian slip, and you actually meant "more stuff". :( npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Man, LLMs really drive home the lesson that people differ *greatly* in how much the care whether the statements they make are accurate. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…d0jr Here on Mastodon the video did not appear. It did in the RSS feed for your blog: https://youtu.be/J-UUwG3L9IY?si=RUkK5loGg-s6kuXa npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…4xpq @nprofile…g2n5 @nprofile…a6hr I think both things are true: politics in the US are heavily polarized between Democrats and Republicans, but also neither of them is leftist: the Democrats are centrists and the Republicans are far right. Occasional leftist politicians run as Democrats, not because that party is left-leaning, but because in that country there is only one other party and it is a far right one. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín I implemented org-babel support for 3 array languages I like a lot: Goal¹, BQN² and growler/k³. These languages are great for data munging so I find it very handy to use them in #OrgMode to process data stored in org tables. You can grab my implementations from my Emacs configuration at: https://github.com/oantolin/emacs-config/blob/master/my-lisp/ob-goal.el https://github.com/oantolin/emacs-config/blob/master/my-lisp/ob-bqn.el https://github.com/oantolin/emacs-config/blob/master/my-lisp/ob-k.el ¹ https://codeberg.org/anaseto/goal ² https://mlochbaum.github.io/BQN/ ³ https://codeberg.org/growler/k, forked from https://codeberg.org/ngn/k #Emacs #ArrayProgramming npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…tfwq hahaha, yes probably! npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…tfwq Wow. Thanks for checking —it's something I didn't want to do on my phone. Version 3.0 is so much faster, updating is low-hanging fruit. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Why is LaTeX rendering on arXiv abstracts so slow? Are they still using MathJax 2.0? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…4hp5 @nprofile…t6k2 After reading what your wife thought, I took a look at some reviews and it gave me flashbacks of reading my student evaluations: one review sides with your wife on the need for editing, calling it "a tedious, bloated epic"; another review calls it "tightly constructed". When I taught undergrads in the US, I remember getting student evaluations, from the same class, one which said I was "the best math teacher I've ever had" and one which said "I don't know how the university lets him teach". npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…pfuj I do 2x, except for certain accents which force me down to 1.5x. One thing I've noticed is that for complicated stuff, like a video of a math reseach seminar, listening at 2x forces me to pay attention whereas at 1x I often get distracted and have to rewind a bit. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…xuzd "blog first, then meet" sounds like such a good idea. Have you been doing it long? How do others take to it? How well does it work? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…xuzd I won't use it all until I can submit to journals in Typst. Why learn a second document language similar to LaTeX when I don't need to? I learn programming languages for fun, not document markup languages (I guess Typst is both... maybe I should do Advent of Code in Typst —but definitely not mathematical documents until journals stop requiring LaTeX source.) npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…xuzd Wow, I didn't know metadata with that effect could even be crafted. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín What's up with people trying to convince me to use Typst? Do they think I like LaTeX? I use it because that's what the journals ask for! If journals accepted Typst source files, I'd give it a shot. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…xuzd I'd call it "conversion", in fact I think a lot of people already use that word when explaining what either "coercion" or "casting" mean. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6pyy I found the author of that brilliant meme! It's Davide Castelvecchi, using a meme format devised by mathstodon don, @nprofile…tfwq! See this blog post for other nice fake math books: https://aperiodical.com/2022/05/didnt-graduate-texts-in-mathematics/ npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6pyy https://media.mathstodon.xyz/media_attachments/files/115/967/568/344/012/444/original/63e23b4fc6497186.png npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…a3ey Did you the French Mathematical Society had decided not to attend the ICM? https://smf.emath.fr/actualites-smf/icm-2026-motion-du-ca npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…xuzd Thanks for explaining that. It does sound very cool. I think the workflow you mentioned is something that I've avoided in git because the few times I've tried it, it seemed like a hassle. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…xuzd I imagine you were using git before. What makes Jujutsu so much more convenient? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín There is much truth to this post about about #math textbooks. https://media.mathstodon.xyz/media_attachments/files/115/956/870/326/807/020/original/8abb41b70b5f11cc.png npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…g0zc "Random find of the day". "Random"? I see what you did there! npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…t6k2 Let's move on to something where we don't agree, then. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Great line I just heard an interviewer say: "Can we move on to some area where we don't completely agree?" npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…q443 Colby is another decent type of cheese originating in the US. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…4hp5 Maybe that's the key! Maybe the methodology is that you compute some global "humanities score" for each university and then "normalize" by dividing by the number of humanities departments. 😛 npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…4hp5 I agree that the MIT claim is very suspicious, a little funny too. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…q443 In case it is just you please stop visiting the website so that it doesn't get worse for the rest of us. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…4hp5 On my phone it lets me scroll the list to see past the fourth one. I haven't tried on a desktop computer yet. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín I was so naive: I thought that once I passed my qualifying exams I'd never feel stressed by qualifying exams ever again! I failed to take into account I'd one day have graduate students, like them and empathize with them. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…a3ey I misunderstood, I thought the errata were missing, but only part of them are. Sorry for unnecessary comment. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…a3ey This doesn't answer your question, but one of the errata was probably about a gap in his proof of the Jordan curve theorem I found. We wrote a short corrigendum explaining the gap and two ways to fill it in: https://webhomes.maths.ed.ac.uk/~v1ranick/jordan/brouwer-cor-fun.pdf npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…rrqe Not wanting reference documentation is complete unrelatable to me! My guess is that you either have a much better memory than I do, or are working with systems with bad reference documentation. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…8eua It's probably just a typo for "among us", the popular videogame that features characters that look like that shape. @nprofile…sn9y npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…w8t5 Not telling you the conclusion of their own work seems really weird to me! To a first approximation nobody cares what I do and nobody has read my papers (I'm hardly unique in this, of course), so I jump on any opportunity to tell people about my work. I would have expected others to feel the same way. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…rrqe Gotta chase those disambiguation clicks! (It actually works on me, I'm like: "I wonder what they meant".) npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…ztfm I think after 6 months it is always an acceptable time to ask about a paper. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…rrqe @nprofile…h3ed You're right Jon that automorphisms of P_G^abs are of the form mu(_, u), but the map r(u) = mu(_,u) is not a homomorphism G --> Aut(P_G^abs), because r(u) o r(v) = r(vu). You want r(u) = mu(_,u^{-1}) instead. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…8eua @nprofile…p3nn I wanted to say this, thanks for saving me the effort. (Except I would have said "we" since I only sound like an American.) npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…fhty I don't know, I kind of want the fields that use lambda to keep using it. It's a nice reminder that I'm leaving mainstream math and entering some adjacent land, like computer science or certain branches of logic,with their own language and customs. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…w8t5 This reminds me of the time I told a friend that even if you define functions as sets of pairs everyone thinks of them as "rules". He swore he actually thought of them as sets of pairs and I could get him to budge on that. But a couple of weeks later I caught him talking about the graph of a function and I said: "don't you mean the function?". npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…rrqe If I were your student I would ignore your distinction and think of it as part of the course material. I'd tell people "I learned this in Jon's course" without adding "of course, it was not part of the material". npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…rrqe As a counterpointal anecdote, as a student I always wanted to know what was true even if the proof was too advanced for me at the time. A course with a large percentage of unprovable-in-the-course claims would be frustrating, no doubt, but I always enjoyed a sprinkling of trailers for future math. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…u6hy I work at UNAM (Universidad Nacional Autónoma de México), but not at UNAM (University of Namibia). npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…fhty That's done with a nice Galois theory trick. Given an automorphism F of the field of complex numbers and a representation G --> GL(n,C) you get a new representation by applying F to all entries of the matrices. If you start with an irreducible representation the F-twisted one is also irreducible (because you could un-F-twist any decomposition). This means that automorphisms of C permute the rows of the character table, and this they fix the column sums. Therefore the column sums are rational numbers. But all entries of the table are algebraic integers; so the column sums are both rational numbers and algebraic integers, which makes them integers. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Today I figured out a cute representation theory fact that must be well-known. The adjoint representation of a finite group G is a representation on the vector space C[G] but with the action given on the basis via g·x := gxg⁻¹. What's the decomposition of this representation into irreducibles? Well, the irreducible representation with character χ occurs with multiplicity given by the sum of the row of the character table corresponding to χ! I didn't even know before today that the row-sums of the character table were non-negative integers! npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…rrqe Is this why you were complaining about recurrence relations that mention n/2 in another post? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…w8t5 I wasn't familiar with that Freyd quote! It makes me feel like I was on the right track when I wrote this in a survey on infinity-categories (section 2.4 of https://www.matem.unam.mx/~omar/papers/infinity-survey.pdf): While it is not reasonable to expect that category theory will swoop in and solve problems from other fields of mathematics, phrasing things categorically does help spot analogies between different fields and to pinpoint where the hard work needs to happen: often arguments are a mix of “formal” parts, which depend very little on the detailed structure of the objects being studied, and “specific” parts which involve understanding their distinguishing properties; categorical language makes short work of many formal arguments, thus highlighting the remainder, the “essential mathematical content” of an argument. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…rrqe That's not a reason against naming things after people, since the problem of having multiple inequivalent definitions also happens to term that are not named after people. In fact, I would guess that problem happens a little less with things named after people. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…ztfm It tricked me into spending a few minutes looking at it. I stopped browsing when the definition of the chain complex used didn't make sense. https://mathstodon.xyz/@oantolin/115418057236389832 npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…2k3a Why did you decide to add Helm support? What does the Helm-specific interface do that the completing-read version doesn't do under Helm? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…w8t5 For what it's worth, I don't find the nLab to be wrong often on topics I'm comfortable with. Wikipedia, of course is pretty good too, but there are many topics you can only find on nLab. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín Where does the r in American's pronunciation of Gödel (sounds like "girdle") come from? I can't remember right now if native English speakers from other countries do that too. Do they? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…yu7x Beautiful! npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…59k6 I think I might hang out with too many constructivists on Mastodon. My first instinct was to correct you, to say you probably meant inhabited rather than non-empty, but... maybe not. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 The first 3 of your 4 reasons proof assistants are interesting are some of the reasons I think mathematics (whether or not formalized) is interesting. Which I guess makes sense, but maybe I'm slightly disappointed your reasons aren't more specific to proof assistants. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 I casually tried opening that link in Emacs's browser and learned Forester actually produces XML! And since you were complaining about the proposal to remove XSLT from the web platform a few days ago (from which I learned browsers come with XSLT!), my guess is that Forester is rendered by XSLT in my browser. That's pretty neat, but it means I need a browser with XSLT. Fortunately I can easily tell Emacs to always open your website in Firefox. 😛 npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…r9rs This reminded me of a story that Jon Bentley tells in More Programming Pearls (A very fun book!). https://media.mathstodon.xyz/media_attachments/files/115/067/031/042/944/623/original/1b6d540cda6471cb.png https://media.mathstodon.xyz/media_attachments/files/115/067/034/637/937/168/original/1eaacc4eec56a8c5.png npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 I did not know about metaweblog, it's good there's a standard. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 The feed reader I use, Inoreader, has labels (but calls them folders, which is probably not a bad idea: if you call them labels people will ask you to implement folders :D) and does deduplication. I haven't tested the deduplication function of Inoreader for two different reasons: (1) it's only for paid users and I am happy with the free version, (2) I never see duplicate posts in different feeds (I do see duplicate posts within a single feed sometimes, though). Being able to publish from your feed reader sounds intriguing. Where would those published feeds be hosted? Are you planning to add, I don't know, Wordpress integration or Micro.blog integration (both of which you mentioned)? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…pmdx I wonder if it'll be much smaller than usual because people are afraid to travel to the US. The Mathematical Congress of the Americas was held in Miami this month and some people told me that in some sessions close to half the speakers cancelled (I was one of the speaker who cancelled, so I had to ask a braver colleague who did go). npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…fa4k Arguably this stick insect is both! Also, they've changed illusive to elusive on the website already, I only see illusive in the link preview here on Mastodon. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…m4ns @nprofile…e9rt I'd say that while these are techincally under C-c and follow the letter of the law of the question, they don't really count because C-c <letter> is meant for user key bindings. If you had some C-c C-<letter> that would be spicier. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 It's funny that happens in functorial semantics. I never hear people say that in other categories: "a set is just an inclusion from the empty set", "a group is just a homomorphism from the trivial group", "a vector space is just a linear transformation from the zero space". Those things are all true, of course, but nobody finds them useful. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…pmdx Then I got nothing. :) npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…v2av I don't understand: which field should have switched from using 1-category to what else? I have no guesses about which field you mean,but about what to switch to I would guess you mean 2-categories or (oo,1)-categories or (oo,oo)-categories. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 Ouch. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…pmdx If people can think of an alternative section title that doesn't have formulas, rather than use that command you mentioned, I'd advise using the formula-less section title. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín You know how people advise you not to use mathematical formulas in section titles in LaTeX? Listen to them! https://media.mathstodon.xyz/media_attachments/files/114/888/870/407/228/144/original/61e794b3e6e090c9.jpg npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 Do you know how it did it? Maybe a weight inversely proportional to publication frequency? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 Oh, I see the comma and the truncated other feed name now. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6kk0 I'm confused: how an I see that from the screenshot? npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…pmdx That would work, but it's almost the same length as "(n-1)-connected pi_n-finite" which had the advantage of not even requiring a definition! npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…pmdx I don't think that's too bad, you could certainly use that term, but it isn't what I would have guessed "virtually n-connected" meant: for spaces, I think of "virtually" as being related to finite covers, so I would have guessed that "virtually n-connected" meant the space is connected, pi_1 is finite and the universal cover is n-connected. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín It's a little odd to me that mathematicians use monads for their categories of algebras but functional programmers use them for their Kleisli categories. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…6cfc I didn't know that about the HoTT book but once I knew, I did immediately guess it must be Mike Shulman. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…hszg Well, ChatGPT is the poster boy for LLMs, so BC and AC would work, but to avoid confusion with COVID we could use L for LLM: BL and AL. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín I think I might edit my CV to add this next to the date I got my degree: "(5 years before the release of ChatGPT)". npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…fa4k It bothers me a little bit that it has both "National" and "of Athens" in the name. npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín ChatGPT kept telling people this software had a certain feature that it didn't have, so the developers decided to implement it. Normally *people* use ChatGPT to vibe code, this is the first instance I'm aware of of *ChatGPT* using people to vibe code! https://www.holovaty.com/writing/chatgpt-fake-feature/ npub17mjld0zpmqv8uam9grchpt02kmgdwxlj7m3ede9r5ueefcstpcwqfjrup0 Omar Antolín @nprofile…t9cc For visitors I think the main risk is the entry, not the subsequent visit if you are allowed to enter.