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(*         *      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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(** * DecimalR  Proofs that conversions between decimal numbers and [R] are bijections. *)

(* Specifications: *)
Lemma of_IQmake_to_decimal num den :
match IQmake_to_decimal num den with
| None => True
| Some (DecimalExp _ _ _) => False
| Some (Decimal i f) =>
of_decimal (Decimal i f) = IRQ (QArith_base.Qmake num den)
end.
Lemma of_to (q:IR) : forall d, to_decimal q = Some d -> of_decimal d = q.
Lemma to_of (d:decimal) : to_decimal (of_decimal d) = Some (dnorm d).
(** Some consequences *)
Lemma to_decimal_inj q q' :
to_decimal q <> None -> to_decimal q = to_decimal q' -> q = q'.
Lemma to_decimal_surj d : exists q, to_decimal q = Some (dnorm d).
Lemma of_decimal_dnorm d : of_decimal (dnorm d) = of_decimal d.
Lemma of_iff d d' : of_decimal d = of_decimal d' <-> dnorm d = dnorm d'.