module type S = sig
  type elt
  type 'a node = Nil | Cons of elt * 'a

  module rec Node :
  sig
    include Hcons.S with type data = Data.t
  end
  and Data : sig
    include Hashtbl.HashedType with type t = Node.t node
  end
  type data = Data.t
  type t = Node.t
  val hash : t -> int
  val uid : t -> Uid.t
  val make : data -> t
  val equal : t -> t -> bool
  val nil : t
  val node : t -> t node
  val cons : ?sorted:bool -> elt -> t -> t
  val hd : t -> elt
  val tl : t -> t
  val fold : (elt -> 'a -> 'a) -> t -> 'a -> 'a
  val map : (elt -> elt) -> t -> t
  val iter : (elt -> 'a) -> t -> unit
  val rev : t -> t
  val rev_map : (elt -> elt) -> t -> t
  val length : t -> int
  val mem : elt -> t -> bool
  val stats : unit -> unit
  val init : unit -> unit
end

module Make (H : Hcons.SA) : S with type elt = H.t