∀ {α : Type u_1} {β : α → Type u_2} [inst : Ord α] (k : α → Ordering) (l : Std.DTreeMap.Internal.Impl α β)
  (motive :
    (m : Std.DTreeMap.Internal.Impl α β) →
      (Std.DTreeMap.Internal.Impl.contains' k l = true → Std.DTreeMap.Internal.Impl.contains' k m = true) → Sort u_3)
  (hm :
    Std.DTreeMap.Internal.Impl.contains' k l = true →
      Std.DTreeMap.Internal.Impl.contains' k Std.DTreeMap.Internal.Impl.leaf = true)
  (h_1 :
    (hm :
        Std.DTreeMap.Internal.Impl.contains' k l = true →
          Std.DTreeMap.Internal.Impl.contains' k Std.DTreeMap.Internal.Impl.leaf = true) →
      motive Std.DTreeMap.Internal.Impl.leaf hm)
  (h_2 :
    (size : ℕ) →
      (k' : α) →
        (v' : β k') →
          (l_1 r : Std.DTreeMap.Internal.Impl α β) →
            (hm :
                Std.DTreeMap.Internal.Impl.contains' k l = true →
                  Std.DTreeMap.Internal.Impl.contains' k (Std.DTreeMap.Internal.Impl.inner size k' v' l_1 r) = true) →
              motive (Std.DTreeMap.Internal.Impl.inner size k' v' l_1 r) hm),
  (match Std.DTreeMap.Internal.Impl.leaf, hm with
    | Std.DTreeMap.Internal.Impl.leaf, hm => h_1 hm
    | Std.DTreeMap.Internal.Impl.inner size k' v' l_1 r, hm => h_2 size k' v' l_1 r hm) =
    h_1 hm