(************************************************************************)
(*         *      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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Local Open Scope R_scope.
Local Ltac Tauto.intuition_solver ::= auto with rorders real.
(** * Preliminaries lemmas *)

Lemma f_incr_implies_g_incr_interv : forall f g:R->R, forall lb ub,
lb < ub ->
(forall x y, lb <= x -> x < y -> y <= ub -> f x < f y) ->
(forall x, f lb <= x -> x <= f ub -> (comp f g) x = id x) ->
(forall x , f lb <= x -> x <= f ub -> lb <= g x <= ub) ->
(forall x y, f lb <= x -> x < y -> y <= f ub -> g x < g y).