(**************************************************************************) (* ___ *) (* ||M|| *) (* ||A|| A project by Andrea Asperti *) (* ||T|| *) (* ||I|| Developers: *) (* ||T|| The HELM team. *) (* ||A|| http://helm.cs.unibo.it *) (* \ / *) (* \ / This file is distributed under the terms of the *) (* v GNU General Public License Version 2 *) (* *) (**************************************************************************) (* This file was automatically generated: do not edit *********************) include "CoRN.ma". (* $Id: CalculusTheorems.v,v 1.6 2004/04/23 10:00:57 lcf Exp $ *) include "ftc/Rolle.ma". include "tactics/DiffTactics3.ma". (* UNEXPORTED Opaque Min Max. *) (* UNEXPORTED Section Various_Theorems *) (*#* *Calculus Theorems This file is intended to present a collection of miscellaneous, mostly technical results in differential calculus that are interesting or useful in future work. We begin with some properties of continuous functions. Every continuous function commutes with the limit of a numerical sequence (sometimes called Heine continuity). *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/Continuous_imp_comm_Lim.con" as lemma. (*#* This is a tricky result: if [F] is continuous and positive in both [[a,b]] and [(b,c]], then it is positive in [[a,c]]. *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/Continuous_imp_pos.con" as lemma. (*#* Similar results for increasing functions: *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/strict_inc_glues.con" as lemma. inline procedural "cic:/CoRN/ftc/CalculusTheorems/strict_inc_glues'.con" as lemma. inline procedural "cic:/CoRN/ftc/CalculusTheorems/strict_dec_glues.con" as lemma. inline procedural "cic:/CoRN/ftc/CalculusTheorems/strict_dec_glues'.con" as lemma. (*#* More on glueing intervals. *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/olor_pos_clor_nonneg.con" as lemma. inline procedural "cic:/CoRN/ftc/CalculusTheorems/olor_pos_olcr_nonneg.con" as lemma. inline procedural "cic:/CoRN/ftc/CalculusTheorems/olor_pos_clcr_nonneg.con" as lemma. (*#* Any function that has the null function as its derivative must be constant. *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/FConst_prop.con" as lemma. (*#* As a corollary, two functions with the same derivative must differ by a constant. *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/Feq_crit_with_const.con" as lemma. (*#* This yields the following known result: any differential equation of the form [f'=g] with initial condition [f(a) [=] b] has a unique solution. *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/Feq_criterium.con" as lemma. (*#* Finally, a well known result: any function with a (strictly) positive derivative is (strictly) increasing. Although the two lemmas look quite similar the proofs are completely different, both from the formalization and from the mathematical point of view. *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/Derivative_imp_resp_less.con" as lemma. inline procedural "cic:/CoRN/ftc/CalculusTheorems/Derivative_imp_resp_leEq.con" as lemma. inline procedural "cic:/CoRN/ftc/CalculusTheorems/Derivative_imp_resp_less'.con" as lemma. (*#* From these results we can finally prove that exponentiation to a real power preserves the less or equal than relation! *) (* UNEXPORTED Opaque nring. *) (* UNEXPORTED Transparent nring. *) inline procedural "cic:/CoRN/ftc/CalculusTheorems/nexp_resp_leEq_odd.con" as lemma. (* UNEXPORTED End Various_Theorems *)