Lean 4 is a programming language recognized by GitHub Linguist and used with .lean.
Quick facts
What is Lean 4
Lean 4 is a programming language recognized by GitHub Linguist and used with .lean.
GitHub Linguist classifies Lean 4 as a programming language, typically using extensions such as .lean.
File extensions:
Frequently asked questions
Lean 4 is a programming language recognized by GitHub Linguist and used with .lean.
Common extensions include .lean.
Sources & standards
Updated 2026-08-18