- [<] Tutorial World #LEAN ⏳ 2025-02-17 📅 2025-02-21
 - [ ] Addition World #LEAN 📅 2025-02-28 ⏳ 2025-02-23 
 - [ ] Implication World #LEAN 📅 2025-03-07 ⏳ 2025-03-02 
 - [ ] Multiplication World #LEAN 📅 2025-03-07 ⏳ 2025-03-07 
 - [ ] Schedule further worlds #LEAN 📅 2025-03-07 ⏳ 2025-03-07