Jesse Alama
@jessealama.net
Math and programming. Lean, JS, Racket. American. Igalian.
The 2026 edition of the ITP (Interactive Theorem Proving) conference back in October featured a #lean event. It was great to be there and connect with so many Lean folks. The videos are finally available: www.youtube.com/playlist?lis...
ITP 2025 Lean Workshop
Share your videos with friends, family, and the world
www.youtube.com
November 14, 2025 at 9:24 AM
The 2026 edition of the ITP (Interactive Theorem Proving) conference back in October featured a #lean event. It was great to be there and connect with so many Lean folks. The videos are finally available: www.youtube.com/playlist?lis...
Reposted by Jesse Alama
Leaning In! 2026 is ON!
If you like #lean and are in Berlin, Germany, Europe, or anywhere on Earth, you are invited.
We've got a room at Spielfeld in Berlin. See you on March 12th!
More information, including tickets and the CfP, here: leaning.in/2026/
If you like #lean and are in Berlin, Germany, Europe, or anywhere on Earth, you are invited.
We've got a room at Spielfeld in Berlin. See you on March 12th!
More information, including tickets and the CfP, here: leaning.in/2026/
Leaning In! 2026
Leaning In! is a one-day workshop dedicated to the Lean programming language and proof assistant.
leaning.in
October 26, 2025 at 7:54 PM
Leaning In! 2026 is ON!
If you like #lean and are in Berlin, Germany, Europe, or anywhere on Earth, you are invited.
We've got a room at Spielfeld in Berlin. See you on March 12th!
More information, including tickets and the CfP, here: leaning.in/2026/
If you like #lean and are in Berlin, Germany, Europe, or anywhere on Earth, you are invited.
We've got a room at Spielfeld in Berlin. See you on March 12th!
More information, including tickets and the CfP, here: leaning.in/2026/
Fascinating talk by Kevin Buzzard about where he sees math going, why it has a big problem (for some time now, even predating the internet), and why #lean might be part of the solution. hackaday.com/2025/10/08/w...
Where Is Mathematics Going? Large Language Models And Lean Proof Assistant
If you’re a hacker you may well have a passing interest in math, and if you have an interest in math you might like to hear about the direction of mathematical research. In a talk on this top…
hackaday.com
October 11, 2025 at 8:24 AM
Fascinating talk by Kevin Buzzard about where he sees math going, why it has a big problem (for some time now, even predating the internet), and why #lean might be part of the solution. hackaday.com/2025/10/08/w...
Really excited to see the #lean Mathlib Initiative take off. Here’s their new web page. Mathlib is such a huge, and growing, project; this help from Renaissance Philanthropy is very welcome.
The Mathlib Initiative
The Mathlib Initiative supports the development of mathematical libraries in the Lean theorem prover.
mathlib-initiative.org
October 9, 2025 at 2:31 PM
Really excited to see the #lean Mathlib Initiative take off. Here’s their new web page. Mathlib is such a huge, and growing, project; this help from Renaissance Philanthropy is very welcome.
TIL In Lean you can output the axioms that a proof depends on using a simple `#print axioms` command.
Axioms
Axioms are postulated constants. While the axiom's type must itself be a type (that is, it must have type Sort u), there are no further requirements. Axioms do not reduce to other terms.
lean-lang.org
October 5, 2025 at 12:58 PM
TIL In Lean you can output the axioms that a proof depends on using a simple `#print axioms` command.
Reposted by Jesse Alama
Even if you didn't have the chance to listen to any of the amazing Igalia Chats - it's time for you to start with a really good chat about #Webassembly, with the one and only @wingolog.org . open.spotify.com/episode/0DmQ...
Wingo on Wasm
open.spotify.com
September 3, 2025 at 1:41 PM
Even if you didn't have the chance to listen to any of the amazing Igalia Chats - it's time for you to start with a really good chat about #Webassembly, with the one and only @wingolog.org . open.spotify.com/episode/0DmQ...
I was reminded of the Blueprint tool for sketching mathematical profs in Lean. I haven’t used it yet but I’m going to see if this can help me structure my work. Also curious to see how Blueprint applies in other scenarios such as software verification.
GitHub - PatrickMassot/leanblueprint: plasTeX plugin to build formalization blueprints.
plasTeX plugin to build formalization blueprints. Contribute to PatrickMassot/leanblueprint development by creating an account on GitHub.
github.com
October 5, 2025 at 8:24 AM
I was reminded of the Blueprint tool for sketching mathematical profs in Lean. I haven’t used it yet but I’m going to see if this can help me structure my work. Also curious to see how Blueprint applies in other scenarios such as software verification.
Some reflections by Terence Tao on different levels, of formalization and rigor in math. This was offered as a discussion topic in the afternoon session of the Lean workshop at ITP 2026 but we didn’t really get around to it.
There’s more to mathematics than rigour and proofs
The history of every major galactic civilization tends to pass through three distinct and recognizable phases, those of Survival, Inquiry and Sophistication, otherwise known as the How, Why, and Wh…
terrytao.wordpress.com
October 4, 2025 at 12:58 PM
Some reflections by Terence Tao on different levels, of formalization and rigor in math. This was offered as a discussion topic in the afternoon session of the Lean workshop at ITP 2026 but we didn’t really get around to it.
This is a real eye-opening article where @ghuntley.com builds a compiler for a new language using LLVM and the amazing technique he calls Ralph Wiggum.
Ralph Wiggum as a "software engineer"
😎Here's a cool little field report from a Y Combinator hackathon event where they put Ralph Wiggum to the test. "We Put a Coding Agent in a While Loop and It Shipped 6 Repos Overnight"…
ghuntley.com
October 4, 2025 at 8:24 AM
This is a real eye-opening article where @ghuntley.com builds a compiler for a new language using LLVM and the amazing technique he calls Ralph Wiggum.
I haven’t yet dived in to git worktrees but as I continue to learn and reflect more on AI-assisted working, I realize this is pretty much the feature i need. This article made things click.
Claude Code - AI Pair Programming Assistant | ClaudeCode.io
Transform your development workflow with Claude Code, the most advanced AI coding assistant powered by Claude Opus 4.1 and Claude Sonnet 4.5.
ClaudeCode.io
October 3, 2025 at 12:58 PM
I haven’t yet dived in to git worktrees but as I continue to learn and reflect more on AI-assisted working, I realize this is pretty much the feature i need. This article made things click.
Reposted by Jesse Alama
No more juggling CommonJS and faux-ESM. @joyeecheung.bsky.social revealed how Node.js is moving to full ESM and why the future looks brighter for developers. #NordicJS #NordicJS2025
October 3, 2025 at 9:55 AM
No more juggling CommonJS and faux-ESM. @joyeecheung.bsky.social revealed how Node.js is moving to full ESM and why the future looks brighter for developers. #NordicJS #NordicJS2025
Reposted by Jesse Alama
OOPSLA 2026 deadline is just a week away! Can you please help us get the word out by sharing? Thanks!
2026.splashcon.org/track/oopsla...
2026.splashcon.org/track/oopsla...
SPLASH 2026 - OOPSLA - SPLASH 2026
Welcome to the website of the SPLASH 2026 conference. We are working hard to fill the website with all related information. Please check back soon!
In the meantime, please consider this overview of th...
2026.splashcon.org
October 2, 2025 at 1:16 PM
OOPSLA 2026 deadline is just a week away! Can you please help us get the word out by sharing? Thanks!
2026.splashcon.org/track/oopsla...
2026.splashcon.org/track/oopsla...
Just arrived in Reykjavik for the #lean workshop as part of ITP 2025 leanprover-community.github.io/itp-2025-lea... I'll be presenting some of my recent work. Looking forwrard to (re)connecting with some fellow Leaners!
Home
Lean Workshop at Interactive Theorem Proving 2025 - 2 October 2025, Reykjavik, Iceland
leanprover-community.github.io
October 2, 2025 at 12:58 PM
Just arrived in Reykjavik for the #lean workshop as part of ITP 2025 leanprover-community.github.io/itp-2025-lea... I'll be presenting some of my recent work. Looking forwrard to (re)connecting with some fellow Leaners!
TIL pre-commit.com
I was just browsing the #lean Mathlib repo toplevel directory and noticed a file with an unusual, but suggestive name. Took a look inside and...love it!
I was just browsing the #lean Mathlib repo toplevel directory and noticed a file with an unusual, but suggestive name. Took a look inside and...love it!
pre-commit
A framework for managing and maintaining multi-language pre-commit hooks.
pre-commit.com
September 22, 2025 at 1:50 PM
TIL pre-commit.com
I was just browsing the #lean Mathlib repo toplevel directory and noticed a file with an unusual, but suggestive name. Took a look inside and...love it!
I was just browsing the #lean Mathlib repo toplevel directory and noticed a file with an unusual, but suggestive name. Took a look inside and...love it!
I'm happy to announce that I've finally wrapped up a proof of Euler's polyhedron formula ("V - E + F = 2") and submitted a PR to Mathlib. I've been working on this in bits and pieces on evenings and weekends.
github.com/leanprover-c...
github.com/leanprover-c...
feat: Euler's polyhedron formula via homological algebra by jessealama · Pull Request #29639 · leanprover-community/mathlib4
Summary This PR adds a proof of Euler's polyhedron formula (V - E + F = 2) using homological algebra, completing theorem #13 from Freek Wiedijk's list of 100 theorems. Mathematical Overview...
github.com
September 14, 2025 at 2:41 PM
I'm happy to announce that I've finally wrapped up a proof of Euler's polyhedron formula ("V - E + F = 2") and submitted a PR to Mathlib. I've been working on this in bits and pieces on evenings and weekends.
github.com/leanprover-c...
github.com/leanprover-c...
TFW you start to realize you're not going to win the game of type tetris.
August 26, 2025 at 12:58 PM
TFW you start to realize you're not going to win the game of type tetris.
The Kimina theorem prover at Project Numina is an amazing piece of technology. This kind of targeted, special-purpose LLMs seems to be just what is needed. They don't even need to be large; "small" LLMs might be just fine. demo.projectnumina.ai
Kimina Prover Demo – AI-Powered Proof Validation in Action
Try the live demo of Kimina Prover – a new AI-powered assistant for interactive proof validation. Test it now!
demo.projectnumina.ai
August 26, 2025 at 8:24 AM
The Kimina theorem prover at Project Numina is an amazing piece of technology. This kind of targeted, special-purpose LLMs seems to be just what is needed. They don't even need to be large; "small" LLMs might be just fine. demo.projectnumina.ai
Just had my first success using the new grind tactic in a #lean proof. I didn't know it was even going to work; I was stuck and reached for it only as a hail-mary desparation move. It worked! Mind blown.
August 23, 2025 at 8:24 AM
Just had my first success using the new grind tactic in a #lean proof. I didn't know it was even going to work; I was stuck and reached for it only as a hail-mary desparation move. It worked! Mind blown.
Happy to announce a new polyfill for the in-progress Ecma TC39 amount proposal! The proposal all about mathematical values together (optionally) with a unit and a precision (understood either as significant or fractional digitis)
proposal-amount
Polyfill for TC39 Amount proposal. Latest version: 20250821.0.0, last published: 7 minutes ago. Start using proposal-amount in your project by running `npm i proposal-amount`. There are no other…
www.npmjs.com
August 22, 2025 at 12:58 PM
Happy to announce a new polyfill for the in-progress Ecma TC39 amount proposal! The proposal all about mathematical values together (optionally) with a unit and a precision (understood either as significant or fractional digitis)
Huge congratulations in order for the #lean Mathlib team for securing a generous donation to help keep things going and improve things further there. Really looking forward to seeing the next steps here. www.renaissancephilanthropy.org/news-and-ins...
Lean FRO and Mathlib receive $10M from XTX Markets Founder Alex Gerko to further advance the use of AI for mathematical research — Renaissance Philanthropy – A brighter future for all through science, technology, and innovation
FOR IMMEDIATE RELEASE July 24, 2025 Contact: media@renphil.org ; richard.hillary@xtxmarkets.com ; pr@convergentresearch.org
www.renaissancephilanthropy.org
August 22, 2025 at 8:24 AM
Huge congratulations in order for the #lean Mathlib team for securing a generous donation to help keep things going and improve things further there. Really looking forward to seeing the next steps here. www.renaissancephilanthropy.org/news-and-ins...
Congratulations to the #lean team on the 4.22 release! This is an exciting one for me for two reasons: the new grind tactic and new support for verification of imperative programs using Hoare triples. lean-lang.org/doc/referenc...
Lean 4.22.0 (2025-08-14)
For this release, 468 changes landed. In addition to the 185 feature additions and 85 fixes listed below there were 15 refactoring changes, 5 documentation improvements, 4 performance improvements, 0…
lean-lang.org
August 21, 2025 at 12:58 PM
Congratulations to the #lean team on the 4.22 release! This is an exciting one for me for two reasons: the new grind tactic and new support for verification of imperative programs using Hoare triples. lean-lang.org/doc/referenc...
Delighted to see the new Institute for Computer-Aided Reasoning in Mathematics. With many overlapping and fellow-travelling communities in academia, industry, even citizen science, a new institute of this kind is probably what we need right now. www.cmu.edu/news/stories...
New NSF Institute at CMU Will Help Mathematicians Harness AI and Advance Discoveries
The Institute for Computer-Aided Reasoning in Mathematics (ICARM) — one of just six mathematics institutes across the U.S. to receive NSF support — will help researchers modernize mathematical…
www.cmu.edu
August 21, 2025 at 8:24 AM
Delighted to see the new Institute for Computer-Aided Reasoning in Mathematics. With many overlapping and fellow-travelling communities in academia, industry, even citizen science, a new institute of this kind is probably what we need right now. www.cmu.edu/news/stories...
The August 2025 Mathlib community call was really great to watch. Thanks for putting it on YouTube. youtu.be/dUWiG12ZQ4g
Mathlib Community Meeting August 8, 2025
youtu.be
August 20, 2025 at 2:58 PM
The August 2025 Mathlib community call was really great to watch. Thanks for putting it on YouTube. youtu.be/dUWiG12ZQ4g
Great overview of the LeanDojo project by Kaiyu Yang from what appears to be a lunchtime CS talk at Stanford. This is all about custom LLM technology for #lean. I haven't kicked the tires on LeanDojo yet but it's on my shortlist of things to explore. youtu.be/qvaR_VXB4fA
LeanDojo: Theorem Proving with Retrieval-Augmented Language Models, Kaiyu Yang et al. - Stanford
main website; LeanDojo: https://leandojo.org/
paper: https://arxiv.org/abs/2306.15626
youtu.be
August 1, 2025 at 8:24 AM
Great overview of the LeanDojo project by Kaiyu Yang from what appears to be a lunchtime CS talk at Stanford. This is all about custom LLM technology for #lean. I haven't kicked the tires on LeanDojo yet but it's on my shortlist of things to explore. youtu.be/qvaR_VXB4fA
I'm learning about zod, a JS package for working with TypeScript data schemes (going well beyond just types). I want to ensure that my compiled TypeScript enforces type checks at runtime in a JS engine. The TS compiler deletes such things, but I want them back! zod.dev
Intro | Zod
Zod 4
zod.dev
July 25, 2025 at 8:24 AM
I'm learning about zod, a JS package for working with TypeScript data schemes (going well beyond just types). I want to ensure that my compiled TypeScript enforces type checks at runtime in a JS engine. The TS compiler deletes such things, but I want them back! zod.dev