text: (**************************************************************************)
  (*                                                                        *)
  (*                                 OCaml                                  *)
  (*                                                                        *)
  (*             Xavier Leroy, projet Cristal, INRIA Rocquencourt           *)
  (*                                                                        *)
  (*   Copyright 1996 Institut National de Recherche en Informatique et     *)
  (*     en Automatique.                                                    *)
  (*                                                                        *)
  (*   All rights reserved.  This file is distributed under the terms of    *)
  (*   the GNU Lesser General Public License version 2.1, with the          *)
  (*   special exception on linking described in the file LICENSE.          *)
  (*                                                                        *)
  (**************************************************************************)
  
  (* Association tables from any ordered type to any type.
     We use the generic ordering to compare keys. *)
  
  type ('a, 'b) t
  
  val empty: ('a, 'b) t
  val add: 'a -> 'b -> ('a, 'b) t -> ('a, 'b) t
  val find: 'a -> ('a, 'b) t -> 'b
  val mem: 'a -> ('a, 'b) t -> bool
  val remove: 'a -> ('a,  'b) t -> ('a, 'b) t
  val iter: ('a -> 'b -> unit) -> ('a, 'b) t -> unit
  val map: ('a -> 'b -> 'c) -> ('a, 'b) t -> ('a, 'c) t
  val fold: ('a -> 'b -> 'c -> 'c) -> ('a, 'b) t -> 'c -> 'c
  
  open Format
  
  val print: (formatter -> 'a -> unit) -> (formatter -> 'b -> unit) ->
             formatter -> ('a, 'b) t -> unit
  