∀ {α : Type u_1} {β : α → Type u_2} (l' r' l'' r'' ℓ : Std.DTreeMap.Internal.Impl α β),
  ℓ.size = l'.size + 1 + r'.size + 1 + l''.size →
    ¬ℓ.size + 1 + r''.size = l'.size + 1 + r'.size + 1 + (l''.size + 1 + r''.size) → False