**Profile**: [Bulhwi Cha](https://github.com/chabulhwi) ![[Bulhwi Cha.png]] **Solutions** : [[zStaging area ==================/Courses and eBooks/Theorem Proving in Lean 4 - Avigad/Theorem Proving in Lean 4 - Avigad]] / [[Solutions - Theorem Proving in Lean 4 - Cha#Solutions by Bulhwi Cha|Solutions by Bulhwi Cha]] --- Author: [[dducoff]] Posted Date: 2026-06-25