**Profile**: [Bulhwi Cha](https://github.com/chabulhwi) ![[Bulhwi Cha.png]] **Solutions** : [[Theorem Proving in Lean 4 - Avigad]] / [[Solutions - Theorem Proving in Lean 4 - Cha#Solutions by Bulhwi Cha|Solutions by Bulhwi Cha]] --- **Posted Date:** 2026-01-19