∀ {α : Type u} {β : α → Type v} {inst : Ord α} {iter : Std.DTreeMap.Internal.Zipper α β} {upper : α}
  {iter_1 : Std.DTreeMap.Internal.Zipper α β} {upper_1 : α},
  { iter := iter, upper := upper } = { iter := iter_1, upper := upper_1 } → iter = iter_1 ∧ upper = upper_1