Make.Keytype t = Key.tinclude Ppx_sexp_conv_lib.Sexpable.S with type t := tval t_of_sexp : Sexplib0.Sexp.t -> tval sexp_of_t : t -> Sexplib0.Sexp.tinclude Comparator.S with type t := tval comparator : (t, comparator_witness) Comparator.comparator