∀ {α : Type u_1} {β : Type u_2} [inst : Ord α] (k : α)
  (motive : (x : Std.DTreeMap.Internal.Impl α fun x => β) → x.Ordered → (∃ a ∈ x, compare a k = Ordering.lt) → Sort u_3)
  (x : Std.DTreeMap.Internal.Impl.leaf.Ordered) (he : ∃ a ∈ Std.DTreeMap.Internal.Impl.leaf, compare a k = Ordering.lt)
  (h_1 :
    (x : Std.DTreeMap.Internal.Impl.leaf.Ordered) →
      (he : ∃ a ∈ Std.DTreeMap.Internal.Impl.leaf, compare a k = Ordering.lt) →
        motive Std.DTreeMap.Internal.Impl.leaf x he)
  (h_2 :
    (size : ℕ) →
      (ky : α) →
        (y : β) →
          (l r : Std.DTreeMap.Internal.Impl α fun x => β) →
            (ho : (Std.DTreeMap.Internal.Impl.inner size ky y l r).Ordered) →
              (he : ∃ a ∈ Std.DTreeMap.Internal.Impl.inner size ky y l r, compare a k = Ordering.lt) →
                motive (Std.DTreeMap.Internal.Impl.inner size ky y l r) ho he),
  (match Std.DTreeMap.Internal.Impl.leaf, x, he with
    | Std.DTreeMap.Internal.Impl.leaf, x, he => h_1 x he
    | Std.DTreeMap.Internal.Impl.inner size ky y l r, ho, he => h_2 size ky y l r ho he) =
    h_1 x he