∀ {α : Type u} [inst : Std.PRange.UpwardEnumerable α] [inst_1 : Std.PRange.InfinitelyUpwardEnumerable α]
  [Std.PRange.LinearlyUpwardEnumerable α] {a b : α}, (Std.PRange.succ a = Std.PRange.succ b) = (a = b)