∀ {α : Type u_1} [inst : TopologicalSpace α] [inst_1 : LinearOrder α] [OrderTopology α] [DenselyOrdered α]
  [FirstCountableTopology α] {x y : α},
  x < y → ∃ u, StrictAnti u ∧ (∀ (n : ℕ), u n ∈ Set.Ioo x y) ∧ Filter.Tendsto u Filter.atTop (nhds x)