Uploaded January 2026 | Updated September 2026, 2 weeks ago
Can you use Lean 4 to better understand visual proof tactics? Can you use visual proof tactics to better understand Lean 4? The answer is "yes", in both directions. In this video, we solve some introductory proofs using both The Incredible Proof Machine (http://incredible.pm) and Lean 4.
We also give an example of solving a proof twice solely in Lean - once by using the tactics mode, and a second time by simply writing a functional program to yield the desired proposition.
The thumbnail painting is Femmes d'Alger dans leur appartement, by Eugène Delacroix
Can you use Lean 4 to better understand visual proof tactics? Can you use visual proof tactics to better understand Lean 4? The answer is "yes", in both directions. In this video, we solve some introductory proofs using both The Incredible Proof Machine (http://incredible.pm) and Lean 4.
We also give an example of solving a proof twice solely in Lean - once by using the tactics mode, and a second time by simply writing a functional program to yield the desired proposition.
The thumbnail painting is Femmes d'Alger dans leur appartement, by Eugène Delacroix
