100% MATCH
895 MERGED PRSPROBLEM DESCRIPTION STYLE
WHY THEM Writes about problem description style in their own reviews.
“Unrelated but this one is computable (maybe the only one?) For example: ```lean abbrev SetTheory.Set.empty_iProd_equiv (X: (∅:Set) → Set) : iProd X ≃ Unit where toFun := fun t ↦ () invFun := fun x ↦ ⟨tuple fun e ↦ False.elim (not_mem_empty _ e.property), by apply tuple_mem_iProd⟩ left_inv := by intro t have h := (mem_iProd _).mp t.property obtain ⟨x, ht⟩ := h ext rw [ht, tuple_inj] ext e have := not_mem_empty e contradiction right_inv := by intro simp ``` Not included because the book has a "why" seemingly for a related question: <img width="1468" height="616" alt="Screenshot 2025-08-07 at 04 16 37" src="https://github.com/user-attachments/assets/edd16e6f-927a-4a37-8bb4-302761ddac53" /> ”