Lean 4
Lean 4 programming language and theorem prover
Lean 4 is both a programming language and an interactive theorem prover, designed to support formal reasoning while also functioning as an efficient and extensible general-purpose language. The project serves researchers, mathematicians, programmers, and formal methods users who need a system for writing machine-checked proofs as well as executable programs in the same environment. One of its defining characteristics is its emphasis on extensibility, since Lean 4 is built to allow users to...