∀ {α : Type u} {r : Std.Rcc α} [inst : LE α] [inst_1 : DecidableLE α] [inst_2 : Std.PRange.UpwardEnumerable α]
  [inst_3 : Std.Rxc.HasSize α] [inst_4 : Std.PRange.LawfulUpwardEnumerable α] [Std.PRange.LawfulUpwardEnumerableLE α]
  [inst_6 : Std.Rxc.IsAlwaysFinite α] [Std.Rxc.LawfulHasSize α], r.toList.length = r.size