∀ {α : Type u} {r : Std.Roo α} [inst : Std.PRange.UpwardEnumerable α] [inst_1 : LT α] [inst_2 : DecidableLT α]
  [inst_3 : Std.PRange.LawfulUpwardEnumerable α] [Std.PRange.LawfulUpwardEnumerableLT α]
  [inst_5 : Std.Rxo.IsAlwaysFinite α],
  r.toList =
    match Std.PRange.succ? r.lower with
    | none => []
    | some next => (next...r.upper).toList