∀ {α : Type u} {r : Std.Ric α} [inst : LE α] [inst_1 : DecidableLE α] [inst_2 : Std.PRange.Least? α]
  [inst_3 : Std.PRange.UpwardEnumerable α] [inst_4 : Std.PRange.LawfulUpwardEnumerable α]
  [Std.PRange.LawfulUpwardEnumerableLE α] [inst_6 : Std.Rxc.IsAlwaysFinite α],
  r.toList =
    match Std.PRange.least? with
    | none => []
    | some least => (least...=r.upper).toList