Halmos
Math forum the server can check
What it does
A community for mathematics where claims carry machine-checked status. Post a proof in Lean and the kernel rules on it.
Does the same job
all alternatives →- MOMathcha – Online Mathematics Editor2017 · mathcha.io · ▲358
- AUA utility for running exhaustiveness checks on “sum types” in Go2017 · github.com · ▲75
- SASocial and context-aware AI platform to do mathJul 2026 · prooftree.ai · ▲5
Hi HN, This is ProofTree, and in TLDR: it is a platform where you can chat with an AI to do math, the way you already do, with context-awareness and knows how you personally do math, connected to the fora of other live human mathematicians. So, when you are talking to an AI about a proof at 3 am, and you need a human expert looking at it, or a discussion around it, like you do on StackExchange, this is it! You need an approved email account to use it, so please write here if you would live to try it out.
More life & fun this month
the category →- TL
Life & fun · 9d ago · louisabraham.github.io
Photosynthesis fires two of your iPhone
Life & fun · 28d ago · photosynthesis.camera
SoloUno▲310Take control of hair pulling, nail biting & skin picking
Life & fun · 28d ago · solouno.io
Scroll through all 43,252,003,274,489,856,000 reachable Rubik's Cube permutations.
Life & fun · 26d ago · everycube.alen.is
Hi HN, I built Eigendrum, a web tool that solves the 2D wave equation for arbitrary shapes so you can hear what they sound like as drums. How it works: * Solves -∇²u = λu using finite element analysis (Kφ = λMφ) on a triangle mesh. * Validated to <0.1% error against closed-form solutions for circles (Bessel zeros) and rectangles. * Sound model factors in strike location, Rayleigh damping, and mallet width. * Includes Kac drums I & II to demonstrate identical sound spectra from different geometries. * No frameworks, build steps, or dependencies. Repo and tests:…
Life & fun · 26d ago · baselashraf81.github.io
Launched alongside, August 2026
the whole month →- TL
Life & fun · 9d ago · louisabraham.github.io
- SA
Hello HN! I found that picking out plausible but diverse skin tones for my digital art and game development projects was kind of difficult, and I got curious about if there was a way to define a color space that made it easy. I've built a color picker and procedural generation algorithm based on the space as well as a bunch of other fun js features and demos throughout the page that use the equations. If you find it interesting, I have lots of explanations of how I built it and what properties the space has. The methodology might be a bit shaky, but hopefully the result is as helpful for…
Life & fun · Aug 2026 · toneyalexander.github.io
I trained a 125M-parameter transformer to autocomplete piano performances in real time (~108 notes/sec on an iPhone 15). The idea is basically GitHub Copilot or Tabnine, except instead of prompting it with code, you prompt it by playing a few notes on a MIDI piano. The model then continues what you played, entirely on-device. The app is free if anyone wants to try it. Happy to answer questions about the model, training, Core ML, or the many things that didn't work.
AI · 16d ago · simedw.com