Treemap.Make
module Key : Key
type 'a t
val refine : Key.t -> inter:('a -> 'a -> 'a) -> join:('a -> 'a -> 'a) -> 'a -> 'a t -> 'a t
val find : Key.t -> 'a t -> 'a
val empty : 'a t
val make_pretty : (Stdlib.Format.formatter -> 'a -> unit) -> Stdlib.Format.formatter -> 'a t -> unit