Lean
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Lean
@leanprover
Lean is a dependently-typed programming language and theorem prover.







Interesting update: a few days ago, Nathanson presented a talk at the New York Number Theory Seminar explaining how Aristotle solved some of his problems.

For each implication, submissions must provide either a @leanprover proof that it is true, or a Lean certificate of a counterexample showing that it is false. Two tracks: Solo: one solver subprocess per problem. Marathon: one solver subprocess handles a batch of problems under a shared global budget.





Did a Keynote talk at PaPoC 2026 workshop on "From Convergence to Confidence: Push-button verification for Replicated Data Types" on verifying RDTs and some very recent work on agentic-proof-oriented programming in Lean. #papoc_2026" target="_blank" rel="nofollow noopener">kcsrk.info/talks#papoc_20…
See fplaunchpad.org/sal.
To my mind, what seems most important here is not so much the results themselves, nor even the particular methods used in the proof. What really matters is the workflow: the closed loop from autonomous discovery of the right constructions, to formal verification of the proof in Lean, to informalised exposition back into a manuscript that mathematicians can read, understand, rewrite, and improve. It suggests a framework in which formal proof is not merely a static final certificate, but an active part of mathematical research: a medium through which ideas are found, organised, tested, explained and made available for human judgment. That dynamic loop is the real story for me. The natural next question is how far it can be pushed.



Max Tegmark says the way through the AI black box may be to deploy its outputs instead. A cat can learn, but it cannot export what it learned. A human scientist can. As intelligence rises, more knowledge may become externalized into code and proofs. Deploy what the mind can verify, not the mind itself.





Tudor Achim (@tachim) is convinced that AI will surpass every human mathematician within the next three years. At the center of that claim is Aristotle, @HarmonicMath's mathematical agent and the first of its kind. When you delegate a reasoning task to Aristotle, the answer it provides will always be correct. Every LLM available today can do math. The problem is that the answers look plausible, and looking plausible is not the same as being right. To catch the errors, you need to already be a professional mathematician. Aristotle does not ask that of you.




Excitining News! Signal Shot is a public moonshot to verify the Signal protocol and its Rust implementation using Lean. It is a joint effort of Signal (Rolfe Schmidt), the Beneficial AI Foundation (Max Tegmark), and the Lean FRO. leodemoura.github.io/blog/2026-4-20… #leanprover #leanlang

Software Verification in Lean 2026 is a one-day open workshop on April 20, with talks by Max Tegmark, Leo de Moura, Son Ho, Derek Sorensen, and Karthikeyan Bhargavan. On-site capacity has been reached. Register to join the livestream: beneficial-ai-foundation.github.io/SVIL2026/





