VSS25: The Lean Programming Language and Theorem Prover

Tuesday 12th August, Morning Session

Talk by Sebastian Ullrich and Joachim Breitner, Lean Focused Research Organization

BACKGROUND:

Lean is a functional programming language that can be also used as an interactive theorem prover. Lean programming primarily involves defining types and functions. This allows your focus to remain on the problem domain and manipulating its data, rather than the details of programming. The Lean project was launched by Leonardo de Moura in 2013 as an open source project, hosted on GitHub.

PREPARATION:

Additional materials may be circulated nearer the day, but students are asked to install Lean 4 on their machines in advance.

For installing Lean 4, please see their download pages. Information about the community of Lean users and the mathematical components library Mathlib can be found at the Lean Community website.

Dr Sebastian Ullrich

Dr Ullrich is a Programming Languages researcher and engineer. He is one of the core contributor to the development of the Lean programming language and theorem prover. After finishing his PhD on the design of the current version of Lean, Lean 4, in 2023, he co-founded the Lean Focused Research Organization together with Leonardo de Moura, the creator of Lean, with the goal of tackling the challenges of scalability, usability, and proof automation in the Lean theorem prover.

Dr Joachim Breitner

Dr Joachim Breitner is Principle Research Software Engineer with the Lean FRO, working on the Lean theorem prover. His research focus is on Functional Programming, especially Haskell and Isabelle, formal verification and theorem proving.