(************************************************************************)
(*         *      The Rocq Prover / The Rocq 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)         *)
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(** * Finite map library *)
(** This file proposes an implementation of the non-dependent interface [FMapInterface.WS] using lists of pairs, unordered but without redundancy. *)
Set Implicit Arguments.
Unset Strict Implicit.
Module Raw (X:DecidableType).
Module Import PX := KeyDecidableType X.
Definition key := X.t.
Definition t (elt:Type) := list (X.t * elt).
Section Elt.
Variable elt : Type.
Notation eqk := (eqk (elt:=elt)).
Notation eqke := (eqke (elt:=elt)).
Notation MapsTo := (MapsTo (elt:=elt)).
Notation In := (In (elt:=elt)).
Notation NoDupA := (NoDupA eqk).
(** * [empty] *)
Definition empty : t elt := nil.
Definition Empty m := forall (a : key)(e:elt), ~ MapsTo a e m.

Lemma empty_NoDup : NoDupA empty.
Definition is_empty (l : t elt) : bool := if l then true else false.