sig
type t
type elt = label
val create : unit -> t
val is_empty : t -> bool
val mem : elt -> t -> bool
val add : elt -> t -> unit
val add_list : elt list -> t -> unit
val singleton : elt -> t
val remove : elt -> t -> unit
val compare : t -> t -> int
val equal : t -> t -> bool
val subset : t -> t -> bool
val iter : (elt -> unit) -> t -> unit
val fold : (elt -> 'a -> 'a) -> t -> 'a -> 'a
val for_all : (elt -> bool) -> t -> bool
val exists : (elt -> bool) -> t -> bool
val filter : (elt -> bool) -> t -> unit
val cardinal : t -> int
val elements : t -> elt list
val min_elt : t -> elt
val max_elt : t -> elt
val choose : t -> elt
val from_list : elt list -> t
val string_of : t -> string
val string_of_complex :
?start_char:string -> ?end_char:string -> t -> string
val laset : t -> LabelSet.t
end