-- Catch special case of induction pattern that uses Mathlib's alternative `induction'` syntax, -- which is used in the Natural Numbers game as just `induction`, overlapping with the parser for -- Lean's default tactic theorem zero_mul (m : Nat) : 0 * m = 0 := by induction m with n n_ih rw [Nat.mul_zero] rw [Nat.mul_succ] rw [Nat.add_zero] rw [n_ih] theorem zero_mul2 (m : Nat) : 0 * m = 0 := by cases m with n rw [Nat.mul_zero] rw [Nat.mul_succ] rw [Nat.add_zero] rw [zero_mul] -- Special case not triggered by empty case analysis theorem zero_mul3 (m : Nat) : 0 * m = 0 := by induction m with theorem zero_mul4 (m : Nat) : 0 * m = 0 := by cases m with