leanprover/lean4

Lean 4 programming language and theorem prover

9,120

stars

39,442

commits

Lean

primary language

Sep 11, 2026

updated

lean-lang.org

lean

lean4

Browse cluster: Lean 4 development tools and ecosystem →

README

This is the repository for Lean 4.

About

Installation

See Install Lean.

Contributing

Please read our Contribution Guidelines first.

Building from Source

See Building Lean.

Contributors

(top 30 of 271)

23,774 commits

5,016 commits

1,535 commits

1,148 commits

See what people are saying

Hacker News (1)

Fermat's Last Theorem in Lean 4

0 points · Sep 5, 2026

X (5)

as of recent, i've been obsessed with formal verification, specifically on breaking them. out of curiosity, i ran winfunc on lean4 and it discovered the following UAF (use-after-free): https://t.co/eFNc8FP4m5 got quickly pached too! :)

@mufeedvh · 9 likes · Sep 9, 2026

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leanprover/lean4

Lean 4 programming language and theorem prover

9,120

stars

39,442

commits

Lean

primary language

Sep 11, 2026

updated

lean-lang.org

lean

lean4

Browse cluster: Lean 4 development tools and ecosystem →

README

This is the repository for Lean 4.

About

Installation

See Install Lean.

Contributing

Please read our Contribution Guidelines first.

Building from Source

See Building Lean.

See what people are saying

Hacker News (1)

Fermat's Last Theorem in Lean 4

0 points · Sep 5, 2026

X (5)

@mufeedvh · 9 likes · Sep 9, 2026

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