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(************************************************************************)
(* * The Coq Proof Assistant / The Coq Development Team *)
(* v * Copyright INRIA, CNRS and contributors *)
(* <O___,, * (see version control and CREDITS file for authors & dates) *)
(* \VV/ **************************************************************)
(* // * This file is distributed under the terms of the *)
(* * GNU Lesser General Public License Version 2.1 *)
(* * (see LICENSE file for the text of the license) *)
(************************************************************************)
module type S =
sig
type t
val compare : t -> t -> int
end
module Pair (M:S) (N:S) = struct
type t = M.t * N.t
let compare (a,b) (a',b') =
let i = M.compare a a' in
if Int.equal i 0 then N.compare b b'
else i
end
module UnorderedPair (M:S) = struct
type t = M.t * M.t
let reorder (a,b as p) =
if M.compare a b <= 0 then p else (b,a)
let compare p p' =
let p = reorder p and p' = reorder p' in
let module P = Pair(M)(M) in P.compare p p'
end
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