The "batteries included" extended library for the Lean programming language and theorem prover
Batteries is an extended standard library for Lean 4, providing a collection of data structures and tactics designed for both computer science and mathematics applications. The project is maintained by the Lean prover community and built in Lean itself, using the Lake build system. It serves as a "batteries included" foundation that other Lean projects can depend on, with particular integration points in the broader Lean ecosystem like Mathlib 4.