import TestGame.Metadata import Mathlib.Data.Set.Basic import Mathlib.Algebra.Parity import Mathlib.Tactic.Ring Game "TestGame" World "SetTheory" Level 21 Title "" Introduction " " open Set Statement "" : 3 ∈ {n : ℕ | Odd n} := by rw [mem_setOf] use 1 ring NewTactic constructor intro rw assumption rcases simp tauto trivial