∀ {α : Type u_1} [inst : Std.PRange.UpwardEnumerable α] [inst_1 : LT α] [inst_2 : DecidableLT α]
  [Std.PRange.LawfulUpwardEnumerable α] [Std.PRange.LawfulUpwardEnumerableLT α] (r : Std.Roo α),
  ∀ a ∈ Std.Roo.Internal.iter r, a ∈ r