∀ {α : Type u_1} {β : α → Type u_2} (motive : Std.DTreeMap.Internal.Impl α β → Sort u_3)
  (h_1 : Unit → motive Std.DTreeMap.Internal.Impl.leaf)
  (h_2 :
    (size : ℕ) →
      (k' : α) →
        (v' : β k') →
          (l' r' : Std.DTreeMap.Internal.Impl α β) → motive (Std.DTreeMap.Internal.Impl.inner size k' v' l' r')),
  (match Std.DTreeMap.Internal.Impl.leaf with
    | Std.DTreeMap.Internal.Impl.leaf => h_1 ()
    | Std.DTreeMap.Internal.Impl.inner size k' v' l' r' => h_2 size k' v' l' r') =
    h_1 ()