val elements : t -> elt listval mem : elt -> t -> boolval iter : ( elt -> unit ) -> t -> unitval fold : ( elt -> 'a -> 'a ) -> t -> 'a -> 'aval filter : ( elt -> bool ) -> t -> tval partition : ( elt -> bool ) -> t -> t * tval for_all : ( elt -> bool ) -> t -> boolval exists : ( elt -> bool ) -> t -> boolval iter_sorted : ( elt -> unit ) -> t -> unitval fold_sorted : ( elt -> 'a -> 'a ) -> t -> 'a -> 'aval subset : t -> t -> boolval intersect : t -> t -> boolval of_list : elt list -> t