sig
type 'a t
val empty : 'a Bag.t
val elt : 'a -> 'a Bag.t
val add : 'a -> 'a Bag.t -> 'a Bag.t
val append : 'a Bag.t -> 'a -> 'a Bag.t
val list : 'a list -> 'a Bag.t
val ulist : 'a Bag.t list -> 'a Bag.t
val concat : 'a Bag.t -> 'a Bag.t -> 'a Bag.t
val map : ('a -> 'b) -> 'a Bag.t -> 'b Bag.t
val umap : ('a -> 'b Bag.t) -> 'a Bag.t -> 'b Bag.t
val iter : ('a -> unit) -> 'a Bag.t -> unit
val fold_left : ('b -> 'a -> 'b) -> 'b -> 'a Bag.t -> 'b
val fold_right : ('a -> 'b -> 'b) -> 'a Bag.t -> 'b -> 'b
val filter : ('a -> bool) -> 'a Bag.t -> 'a Bag.t
val partition : ('a -> bool) -> 'a Bag.t -> 'a Bag.t * 'a Bag.t
val length : 'a Bag.t -> int
val is_empty : 'a Bag.t -> bool
val singleton : 'a Bag.t -> 'a option
val elements : 'a Bag.t -> 'a list
end