# Module type Core_set_intf.Accessors1

    module type Accessors1 = sig .. end

    include Container.S1

    type 'a tree

    type comparator_witness

    val invariants : 'a t -> bool

    val mem : 'a t -> 'a -> bool

    val add : 'a t -> 'a -> 'a t

    val remove : 'a t -> 'a -> 'a t

    val union : 'a t -> 'a t -> 'a t

    val inter : 'a t -> 'a t -> 'a t

    val diff : 'a t -> 'a t -> 'a t

    val symmetric_diff : 'a t -> 'a t -> ('a, 'a) Either.t Sequence.t

    val compare_direct : 'a t -> 'a t -> int

    val equal : 'a t -> 'a t -> bool

    val subset : 'a t -> 'a t -> bool

    val fold_until : 'a t -> init:'b -> f:('b -> 'a -> [ `Continue of 'b | `Stop of 'b ]) -> 'b

    val fold_right : 'a t -> init:'b -> f:('a -> 'b -> 'b) -> 'b

    val iter2 : 'a t ->
           'a t -> f:([ `Both of 'a * 'a | `Left of 'a | `Right of 'a ] -> unit) -> unit

    val filter : 'a t -> f:('a -> bool) -> 'a t

    val partition_tf : 'a t -> f:('a -> bool) -> 'a t * 'a t

    val elements : 'a t -> 'a list

    val min_elt : 'a t -> 'a option

    val min_elt_exn : 'a t -> 'a

    val max_elt : 'a t -> 'a option

    val max_elt_exn : 'a t -> 'a

    val choose : 'a t -> 'a option

    val choose_exn : 'a t -> 'a

    val split : 'a t -> 'a -> 'a t * 'a option * 'a t

    val group_by : 'a t -> equiv:('a -> 'a -> bool) -> 'a t list

    val find_exn : 'a t -> f:('a -> bool) -> 'a

    val find_index : 'a t -> int -> 'a option

    val remove_index : 'a t -> int -> 'a t

    val to_tree : 'a t -> 'a tree

    val to_sequence : ?order:[ `Decreasing | `Increasing ] ->
           ?greater_or_equal_to:'a -> ?less_or_equal_to:'a -> 'a t -> 'a Sequence.t

    val to_map : 'a t ->
           f:('a -> 'b) -> ('a, 'b, comparator_witness) Map.t