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(*         *   The Coq Proof Assistant / The Coq Development Team       *)
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(* <O___,, *       (see CREDITS file for the list of authors)           *)
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(*    //   *    This file is distributed under the terms of the         *)
(*         *     GNU Lesser General Public License Version 2.1          *)
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(*                                                                      *)
(* Micromega: A reflexive tactic using the Positivstellensatz           *)
(*                                                                      *)
(*  Frédéric Besson (Irisa/Inria) 2006-2008                             *)
(*                                                                      *)
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(*Declare ML Module "micromega_plugin".*)
(*Definition Zeval_expr :=  eval_pexpr 0 Z.add Z.mul Z.sub Z.opp  (fun x => x) (fun x => Z.of_N x) (Z.pow).*)
Fixpoint Qeval_expr (env: PolEnv Q) (e: PExpr Q) : Q :=
match e with
| PEc c =>  c
| PEX j =>  env j
| PEadd pe1 pe2 => (Qeval_expr env pe1) + (Qeval_expr env pe2)
| PEsub pe1 pe2 => (Qeval_expr env pe1) - (Qeval_expr env pe2)
| PEmul pe1 pe2 => (Qeval_expr env pe1) * (Qeval_expr env pe2)
| PEopp pe1 => - (Qeval_expr env pe1)
| PEpow pe1 n => Qpower (Qeval_expr env pe1)  (Z.of_N n)
end.
Definition Qeval_expr' := eval_pexpr  Qplus Qmult Qminus Qopp (fun x => x) (fun x => x) (pow_N 1 Qmult).

Lemma QNpower : forall r n, r ^ Z.of_N n = pow_N 1 Qmult r n.