val is_empty : 'a t -> boolval iter : ('a -> unit) -> 'a t -> unitval add : 'a t -> 'a -> unitval add_set : 'a t -> 'a t -> unitval remove : 'a t -> 'a -> unitval remove_set : 'a t -> 'a t -> unitval mem : 'a t -> 'a -> boolval to_list : 'a t -> 'a listval from_list : 'a list -> 'a tval for_all : ('a -> bool) -> 'a t -> boolval exists : ('a -> bool) -> 'a t -> boolval subset_eq : 'a t -> 'a t -> boolval equals : 'a t -> 'a t -> boolval map : ('a -> 'b) -> 'a t -> 'b tval filter : ('a -> bool) -> 'a t -> 'a tval filter_map : ('a -> 'b option) -> 'a t -> 'b tval filter_inplace : ('a -> bool) -> 'a t -> unit