∀ {α : Type u_1} (t : Array.PrefixTable α) (motive : Fin (t.size + 1) → Sort u_2) (k : ℕ) (hk : k < t.size + 1)
  (h_1 : (k : ℕ) → (hk : k < t.size + 1) → motive ⟨k, hk⟩),
  (match ⟨k, hk⟩ with
    | ⟨k, hk⟩ => h_1 k hk) =
    h_1 k hk