no goals
n a : ℕ
x✝ : a ∈ Nat.rfind fun n_1 => (fun m => decide (m = 0)) <$> (↑fun x => 1) (Nat.pair n n_1)
h : (Nat.rfind fun n_1 => (fun m => decide (m = 0)) <$> (↑fun x => 1) (Nat.pair n n_1)).Dom
h✝ : Part.get (Nat.rfind fun n_1 => (fun m => decide (m = 0)) <$> (↑fun x => 1) (Nat.pair n n_1)) h = a
⊢ False
simp at h