val is_empty : 'a t -> bool
val mem : key -> 'a t -> bool
val add : key -> 'a -> 'a t -> 'a t
val update : key -> ( 'a option -> 'a option ) -> 'a t -> 'a t
val singleton : key -> 'a -> 'a t
val remove : key -> 'a t -> 'a t
val merge :
( key -> 'a option -> 'b option -> 'c option ) ->
'a t ->
'b t ->
'c t
val union : ( key -> 'a -> 'a -> 'a option ) -> 'a t -> 'a t -> 'a t
val compare : ( 'a -> 'a -> int ) -> 'a t -> 'a t -> int
val equal : ( 'a -> 'a -> bool ) -> 'a t -> 'a t -> bool
val iter : ( key -> 'a -> unit ) -> 'a t -> unit
val fold : ( key -> 'a -> 'b -> 'b ) -> 'a t -> 'b -> 'b
val for_all : ( key -> 'a -> bool ) -> 'a t -> bool
val exists : ( key -> 'a -> bool ) -> 'a t -> bool
val filter : ( key -> 'a -> bool ) -> 'a t -> 'a t
val partition : ( key -> 'a -> bool ) -> 'a t -> 'a t * 'a t
val cardinal : 'a t -> int
val bindings : 'a t -> (key * 'a) list
val min_binding : 'a t -> key * 'a
val max_binding : 'a t -> key * 'a
val choose : 'a t -> key * 'a
val choose_opt : 'a t -> (key * 'a) option
val split : key -> 'a t -> 'a t * 'a option * 'a t
val find : key -> 'a t -> 'a
val find_opt : key -> 'a t -> 'a option
val map : ( 'a -> 'b ) -> 'a t -> 'b t
val mapi : ( key -> 'a -> 'b ) -> 'a t -> 'b t