CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="fr" dir="ltr"> <head> <meta charset="UTF-8"> <title>Lemme (mathématiques) — Wikipédia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )frwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":[",\t."," \t,"],"wgDigitTransformTable":["",""], "wgDefaultDateFormat":"dmy","wgMonthNames":["","janvier","février","mars","avril","mai","juin","juillet","août","septembre","octobre","novembre","décembre"],"wgRequestId":"5edb9eaf-28ff-4aad-9577-b11ea46d7538","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Lemme_(mathématiques)","wgTitle":"Lemme (mathématiques)","wgCurRevisionId":217707308,"wgRevisionId":217707308,"wgArticleId":108583,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Article contenant un appel à traduction en espagnol","Wikipédia:ébauche mathématiques","Portail:Mathématiques/Articles liés","Portail:Sciences/Articles liés","Projet:Mathématiques/Articles","Lemme de mathématiques","Logique mathématique"],"wgPageViewLanguage":"fr","wgPageContentLanguage":"fr","wgPageContentModel":"wikitext","wgRelevantPageName":"Lemme_(mathématiques)","wgRelevantArticleId":108583,"wgIsProbablyEditable":true, "wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":true,"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"fr","pageLanguageDir":"ltr","pageVariantFallbacks":"fr"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":true,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":4000,"wgRelatedArticlesCompat":[],"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q207505","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled": false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","site","mediawiki.page.ready","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ArchiveLinks","ext.gadget.Wdsearch","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming", "ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.quicksurveys.init","ext.growthExperiments.SuggestedEditSession","wikibase.sidebar.tracking"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=fr&modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=fr&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=fr&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.5"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Lemme (mathématiques) — Wikipédia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//fr.m.wikipedia.org/wiki/Lemme_(math%C3%A9matiques)"> <link rel="alternate" type="application/x-wiki" title="Modifier" href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipédia (fr)"> <link rel="EditURI" type="application/rsd+xml" href="//fr.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://fr.wikipedia.org/wiki/Lemme_(math%C3%A9matiques)"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.fr"> <link rel="alternate" type="application/atom+xml" title="Flux Atom de Wikipédia" href="/w/index.php?title=Sp%C3%A9cial:Modifications_r%C3%A9centes&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="//login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Lemme_mathématiques rootpage-Lemme_mathématiques skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Aller au contenu</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Menu principal" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Menu principal</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Menu principal</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">déplacer vers la barre latérale</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">masquer</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Wikip%C3%A9dia:Accueil_principal" title="Accueil général [z]" accesskey="z"><span>Accueil</span></a></li><li id="n-thema" class="mw-list-item"><a href="/wiki/Portail:Accueil"><span>Portails thématiques</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Sp%C3%A9cial:Page_au_hasard" title="Affiche un article au hasard [x]" accesskey="x"><span>Article au hasard</span></a></li><li id="n-contact" class="mw-list-item"><a href="/wiki/Wikip%C3%A9dia:Contact"><span>Contact</span></a></li> </ul> </div> </div> <div id="p-Contribuer" class="vector-menu mw-portlet mw-portlet-Contribuer" > <div class="vector-menu-heading"> Contribuer </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-aboutwp" class="mw-list-item"><a href="/wiki/Aide:D%C3%A9buter"><span>Débuter sur Wikipédia</span></a></li><li id="n-help" class="mw-list-item"><a href="/wiki/Aide:Accueil" title="Accès à l’aide"><span>Aide</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikip%C3%A9dia:Accueil_de_la_communaut%C3%A9" title="À propos du projet, ce que vous pouvez faire, où trouver les informations"><span>Communauté</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Sp%C3%A9cial:Modifications_r%C3%A9centes" title="Liste des modifications récentes sur le wiki [r]" accesskey="r"><span>Modifications récentes</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Wikip%C3%A9dia:Accueil_principal" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipédia" src="/static/images/mobile/copyright/wikipedia-wordmark-fr.svg" style="width: 7.4375em; height: 1.125em;"> <img class="mw-logo-tagline" alt="l'encyclopédie libre" src="/static/images/mobile/copyright/wikipedia-tagline-fr.svg" width="120" height="13" style="width: 7.5em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Sp%C3%A9cial:Recherche" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Rechercher sur Wikipédia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Rechercher</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Rechercher sur Wikipédia" aria-label="Rechercher sur Wikipédia" autocapitalize="sentences" title="Rechercher sur Wikipédia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Spécial:Recherche"> </div> <button class="cdx-button cdx-search-input__end-button">Rechercher</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Outils personnels"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Apparence"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Modifier l'apparence de la taille, de la largeur et de la couleur de la police de la page" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Apparence" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Apparence</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="//donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_fr.wikipedia.org&uselang=fr" class=""><span>Faire un don</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Sp%C3%A9cial:Cr%C3%A9er_un_compte&returnto=Lemme+%28math%C3%A9matiques%29" title="Nous vous encourageons à créer un compte utilisateur et vous connecter ; ce n’est cependant pas obligatoire." class=""><span>Créer un compte</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Sp%C3%A9cial:Connexion&returnto=Lemme+%28math%C3%A9matiques%29" title="Nous vous encourageons à vous connecter ; ce n’est cependant pas obligatoire. [o]" accesskey="o" class=""><span>Se connecter</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Plus d’options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Outils personnels" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Outils personnels</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="Menu utilisateur" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="//donate.wikimedia.org/wiki/Special:FundraiserRedirector?utm_source=donate&utm_medium=sidebar&utm_campaign=C13_fr.wikipedia.org&uselang=fr"><span>Faire un don</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Sp%C3%A9cial:Cr%C3%A9er_un_compte&returnto=Lemme+%28math%C3%A9matiques%29" title="Nous vous encourageons à créer un compte utilisateur et vous connecter ; ce n’est cependant pas obligatoire."><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Créer un compte</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Sp%C3%A9cial:Connexion&returnto=Lemme+%28math%C3%A9matiques%29" title="Nous vous encourageons à vous connecter ; ce n’est cependant pas obligatoire. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Se connecter</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages pour les contributeurs déconnectés <a href="/wiki/Aide:Premiers_pas" aria-label="En savoir plus sur la contribution"><span>en savoir plus</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Sp%C3%A9cial:Mes_contributions" title="Une liste des modifications effectuées depuis cette adresse IP [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Sp%C3%A9cial:Mes_discussions" title="La page de discussion pour les contributions depuis cette adresse IP [n]" accesskey="n"><span>Discussion</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Sommaire" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Sommaire</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">déplacer vers la barre latérale</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">masquer</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">Début</div> </a> </li> <li id="toc-Étymologie" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Étymologie"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Étymologie</span> </div> </a> <ul id="toc-Étymologie-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Principe" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Principe"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Principe</span> </div> </a> <ul id="toc-Principe-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Lemmes_célèbres" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Lemmes_célèbres"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Lemmes célèbres</span> </div> </a> <ul id="toc-Lemmes_célèbres-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Voir_aussi" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Voir_aussi"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Voir aussi</span> </div> </a> <ul id="toc-Voir_aussi-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Références" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Références"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Références</span> </div> </a> <ul id="toc-Références-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Sommaire" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Basculer la table des matières" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Basculer la table des matières</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Lemme (mathématiques)</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Aller à un article dans une autre langue. Disponible en 49 langues." > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-49" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">49 langues</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%AA%D9%88%D8%B7%D8%A6%D8%A9" title="توطئة – arabe" lang="ar" hreflang="ar" data-title="توطئة" data-language-autonym="العربية" data-language-local-name="arabe" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/Lemma" title="Lemma – azerbaïdjanais" lang="az" hreflang="az" data-title="Lemma" data-language-autonym="Azərbaycanca" data-language-local-name="azerbaïdjanais" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%B0" title="Лема – bulgare" lang="bg" hreflang="bg" data-title="Лема" data-language-autonym="Български" data-language-local-name="bulgare" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Lema_(matem%C3%A0tiques)" title="Lema (matemàtiques) – catalan" lang="ca" hreflang="ca" data-title="Lema (matemàtiques)" data-language-autonym="Català" data-language-local-name="catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-ckb mw-list-item"><a href="https://ckb.wikipedia.org/wiki/%D9%84%DB%8E%D9%85_(%D9%85%D8%A7%D8%AA%D9%85%D8%A7%D8%AA%DB%8C%DA%A9)" title="لێم (ماتماتیک) – sorani" lang="ckb" hreflang="ckb" data-title="لێم (ماتماتیک)" data-language-autonym="کوردی" data-language-local-name="sorani" class="interlanguage-link-target"><span>کوردی</span></a></li><li class="interlanguage-link interwiki-co mw-list-item"><a href="https://co.wikipedia.org/wiki/Lemma_(matematiche)" title="Lemma (matematiche) – corse" lang="co" hreflang="co" data-title="Lemma (matematiche)" data-language-autonym="Corsu" data-language-local-name="corse" class="interlanguage-link-target"><span>Corsu</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Lemma_(matematika)" title="Lemma (matematika) – tchèque" lang="cs" hreflang="cs" data-title="Lemma (matematika)" data-language-autonym="Čeština" data-language-local-name="tchèque" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-cv mw-list-item"><a href="https://cv.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%BC%D0%B0" title="Лемма – tchouvache" lang="cv" hreflang="cv" data-title="Лемма" data-language-autonym="Чӑвашла" data-language-local-name="tchouvache" class="interlanguage-link-target"><span>Чӑвашла</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Hilfssatz" title="Hilfssatz – allemand" lang="de" hreflang="de" data-title="Hilfssatz" data-language-autonym="Deutsch" data-language-local-name="allemand" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-en mw-list-item"><a href="https://en.wikipedia.org/wiki/Lemma_(mathematics)" title="Lemma (mathematics) – anglais" lang="en" hreflang="en" data-title="Lemma (mathematics)" data-language-autonym="English" data-language-local-name="anglais" class="interlanguage-link-target"><span>English</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Lemo" title="Lemo – espéranto" lang="eo" hreflang="eo" data-title="Lemo" data-language-autonym="Esperanto" data-language-local-name="espéranto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Lema_(matem%C3%A1ticas)" title="Lema (matemáticas) – espagnol" lang="es" hreflang="es" data-title="Lema (matemáticas)" data-language-autonym="Español" data-language-local-name="espagnol" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Lemma" title="Lemma – estonien" lang="et" hreflang="et" data-title="Lemma" data-language-autonym="Eesti" data-language-local-name="estonien" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Lema_(matematika)" title="Lema (matematika) – basque" lang="eu" hreflang="eu" data-title="Lema (matematika)" data-language-autonym="Euskara" data-language-local-name="basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%84%D9%85_(%D8%B1%DB%8C%D8%A7%D8%B6%DB%8C%D8%A7%D8%AA)" title="لم (ریاضیات) – persan" lang="fa" hreflang="fa" data-title="لم (ریاضیات)" data-language-autonym="فارسی" data-language-local-name="persan" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Lemma" title="Lemma – finnois" lang="fi" hreflang="fi" data-title="Lemma" data-language-autonym="Suomi" data-language-local-name="finnois" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%9C%D7%9E%D7%94_(%D7%9E%D7%AA%D7%9E%D7%98%D7%99%D7%A7%D7%94)" title="למה (מתמטיקה) – hébreu" lang="he" hreflang="he" data-title="למה (מתמטיקה)" data-language-autonym="עברית" data-language-local-name="hébreu" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%AA%E0%A5%8D%E0%A4%B0%E0%A4%AE%E0%A5%87%E0%A4%AF%E0%A4%BF%E0%A4%95%E0%A4%BE" title="प्रमेयिका – hindi" lang="hi" hreflang="hi" data-title="प्रमेयिका" data-language-autonym="हिन्दी" data-language-local-name="hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Lema_(matematika)" title="Lema (matematika) – croate" lang="hr" hreflang="hr" data-title="Lema (matematika)" data-language-autonym="Hrvatski" data-language-local-name="croate" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Lemma" title="Lemma – hongrois" lang="hu" hreflang="hu" data-title="Lemma" data-language-autonym="Magyar" data-language-local-name="hongrois" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%BC%D5%A5%D5%B4%D5%B4%D5%A1" title="Լեմմա – arménien" lang="hy" hreflang="hy" data-title="Լեմմա" data-language-autonym="Հայերեն" data-language-local-name="arménien" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-ia mw-list-item"><a href="https://ia.wikipedia.org/wiki/Lemma" title="Lemma – interlingua" lang="ia" hreflang="ia" data-title="Lemma" data-language-autonym="Interlingua" data-language-local-name="interlingua" class="interlanguage-link-target"><span>Interlingua</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Lema_(matematika)" title="Lema (matematika) – indonésien" lang="id" hreflang="id" data-title="Lema (matematika)" data-language-autonym="Bahasa Indonesia" data-language-local-name="indonésien" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Lemma_(matematica)" title="Lemma (matematica) – italien" lang="it" hreflang="it" data-title="Lemma (matematica)" data-language-autonym="Italiano" data-language-local-name="italien" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E8%A3%9C%E9%A1%8C" title="補題 – japonais" lang="ja" hreflang="ja" data-title="補題" data-language-autonym="日本語" data-language-local-name="japonais" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%BC%D0%B0" title="Лемма – kazakh" lang="kk" hreflang="kk" data-title="Лемма" data-language-autonym="Қазақша" data-language-local-name="kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EB%B3%B4%EC%A1%B0%EC%A0%95%EB%A6%AC" title="보조정리 – coréen" lang="ko" hreflang="ko" data-title="보조정리" data-language-autonym="한국어" data-language-local-name="coréen" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-ky mw-list-item"><a href="https://ky.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%BC%D0%B0" title="Лемма – kirghize" lang="ky" hreflang="ky" data-title="Лемма" data-language-autonym="Кыргызча" data-language-local-name="kirghize" class="interlanguage-link-target"><span>Кыргызча</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Lemma_(mathematica)" title="Lemma (mathematica) – latin" lang="la" hreflang="la" data-title="Lemma (mathematica)" data-language-autonym="Latina" data-language-local-name="latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Lema" title="Lema – lituanien" lang="lt" hreflang="lt" data-title="Lema" data-language-autonym="Lietuvių" data-language-local-name="lituanien" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%B0" title="Лема – macédonien" lang="mk" hreflang="mk" data-title="Лема" data-language-autonym="Македонски" data-language-local-name="macédonien" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Lema_(matematik)" title="Lema (matematik) – malais" lang="ms" hreflang="ms" data-title="Lema (matematik)" data-language-autonym="Bahasa Melayu" data-language-local-name="malais" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Hulpstelling" title="Hulpstelling – néerlandais" lang="nl" hreflang="nl" data-title="Hulpstelling" data-language-autonym="Nederlands" data-language-local-name="néerlandais" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Lemma_i_matematikk" title="Lemma i matematikk – norvégien nynorsk" lang="nn" hreflang="nn" data-title="Lemma i matematikk" data-language-autonym="Norsk nynorsk" data-language-local-name="norvégien nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Lemma_(matematikk)" title="Lemma (matematikk) – norvégien bokmål" lang="nb" hreflang="nb" data-title="Lemma (matematikk)" data-language-autonym="Norsk bokmål" data-language-local-name="norvégien bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Lemat" title="Lemat – polonais" lang="pl" hreflang="pl" data-title="Lemat" data-language-autonym="Polski" data-language-local-name="polonais" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Lema_(matem%C3%A1tica)" title="Lema (matemática) – portugais" lang="pt" hreflang="pt" data-title="Lema (matemática)" data-language-autonym="Português" data-language-local-name="portugais" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Lem%C4%83_(matematic%C4%83)" title="Lemă (matematică) – roumain" lang="ro" hreflang="ro" data-title="Lemă (matematică)" data-language-autonym="Română" data-language-local-name="roumain" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%BC%D0%B0" title="Лемма – russe" lang="ru" hreflang="ru" data-title="Лемма" data-language-autonym="Русский" data-language-local-name="russe" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Lemma_(mathematics)" title="Lemma (mathematics) – Simple English" lang="en-simple" hreflang="en-simple" data-title="Lemma (mathematics)" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Lemma" title="Lemma – slovaque" lang="sk" hreflang="sk" data-title="Lemma" data-language-autonym="Slovenčina" data-language-local-name="slovaque" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Lemma" title="Lemma – suédois" lang="sv" hreflang="sv" data-title="Lemma" data-language-autonym="Svenska" data-language-local-name="suédois" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-tg mw-list-item"><a href="https://tg.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%BC%D0%B0" title="Лемма – tadjik" lang="tg" hreflang="tg" data-title="Лемма" data-language-autonym="Тоҷикӣ" data-language-local-name="tadjik" class="interlanguage-link-target"><span>Тоҷикӣ</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%9A%E0%B8%97%E0%B8%95%E0%B8%B1%E0%B9%89%E0%B8%87" title="บทตั้ง – thaï" lang="th" hreflang="th" data-title="บทตั้ง" data-language-autonym="ไทย" data-language-local-name="thaï" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tt mw-list-item"><a href="https://tt.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%BC%D0%B0" title="Лемма – tatar" lang="tt" hreflang="tt" data-title="Лемма" data-language-autonym="Татарча / tatarça" data-language-local-name="tatar" class="interlanguage-link-target"><span>Татарча / tatarça</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9B%D0%B5%D0%BC%D0%B0" title="Лема – ukrainien" lang="uk" hreflang="uk" data-title="Лема" data-language-autonym="Українська" data-language-local-name="ukrainien" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Lemma" title="Lemma – ouzbek" lang="uz" hreflang="uz" data-title="Lemma" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="ouzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/B%E1%BB%95_%C4%91%E1%BB%81" title="Bổ đề – vietnamien" lang="vi" hreflang="vi" data-title="Bổ đề" data-language-autonym="Tiếng Việt" data-language-local-name="vietnamien" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%BC%95%E7%90%86" title="引理 – chinois" lang="zh" hreflang="zh" data-title="引理" data-language-autonym="中文" data-language-local-name="chinois" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q207505#sitelinks-wikipedia" title="Modifier les liens interlangues" class="wbc-editpage">Modifier les liens</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Espaces de noms"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Lemme_(math%C3%A9matiques)" title="Voir le contenu de la page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Discussion:Lemme_(math%C3%A9matiques)" rel="discussion" title="Discussion au sujet de cette page de contenu [t]" accesskey="t"><span>Discussion</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Modifier la variante de langue" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">français</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Affichages"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Lemme_(math%C3%A9matiques)"><span>Lire</span></a></li><li id="ca-ve-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&veaction=edit" title="Modifier cette page [v]" accesskey="v"><span>Modifier</span></a></li><li id="ca-edit" class="collapsible vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=edit" title="Modifier le wikicode de cette page [e]" accesskey="e"><span>Modifier le code</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=history" title="Historique des versions de cette page [h]" accesskey="h"><span>Voir l’historique</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Outils de la page"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Outils" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Outils</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Outils</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">déplacer vers la barre latérale</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">masquer</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="Plus d’options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Lemme_(math%C3%A9matiques)"><span>Lire</span></a></li><li id="ca-more-ve-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&veaction=edit" title="Modifier cette page [v]" accesskey="v"><span>Modifier</span></a></li><li id="ca-more-edit" class="collapsible vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=edit" title="Modifier le wikicode de cette page [e]" accesskey="e"><span>Modifier le code</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=history"><span>Voir l’historique</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> Général </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Sp%C3%A9cial:Pages_li%C3%A9es/Lemme_(math%C3%A9matiques)" title="Liste des pages liées qui pointent sur celle-ci [j]" accesskey="j"><span>Pages liées</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Sp%C3%A9cial:Suivi_des_liens/Lemme_(math%C3%A9matiques)" rel="nofollow" title="Liste des modifications récentes des pages appelées par celle-ci [k]" accesskey="k"><span>Suivi des pages liées</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Aide:Importer_un_fichier" title="Téléverser des fichiers [u]" accesskey="u"><span>Téléverser un fichier</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Sp%C3%A9cial:Pages_sp%C3%A9ciales" title="Liste de toutes les pages spéciales [q]" accesskey="q"><span>Pages spéciales</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&oldid=217707308" title="Adresse permanente de cette version de cette page"><span>Lien permanent</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=info" title="Davantage d’informations sur cette page"><span>Informations sur la page</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Sp%C3%A9cial:Citer&page=Lemme_%28math%C3%A9matiques%29&id=217707308&wpFormIdentifier=titleform" title="Informations sur la manière de citer cette page"><span>Citer cette page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Sp%C3%A9cial:UrlShortener&url=https%3A%2F%2Ffr.wikipedia.org%2Fwiki%2FLemme_%28math%25C3%25A9matiques%29"><span>Obtenir l'URL raccourcie</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Sp%C3%A9cial:QrCode&url=https%3A%2F%2Ffr.wikipedia.org%2Fwiki%2FLemme_%28math%25C3%25A9matiques%29"><span>Télécharger le code QR</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Imprimer / exporter </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-create_a_book" class="mw-list-item"><a href="/w/index.php?title=Sp%C3%A9cial:Livre&bookcmd=book_creator&referer=Lemme+%28math%C3%A9matiques%29"><span>Créer un livre</span></a></li><li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Sp%C3%A9cial:DownloadAsPdf&page=Lemme_%28math%C3%A9matiques%29&action=show-download-screen"><span>Télécharger comme PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&printable=yes" title="Version imprimable de cette page [p]" accesskey="p"><span>Version imprimable</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> Dans d’autres projets </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="wb-otherproject-link wb-otherproject-commons mw-list-item"><a href="https://commons.wikimedia.org/wiki/Category:Lemmas" hreflang="en"><span>Wikimedia Commons</span></a></li><li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q207505" title="Lien vers l’élément dans le dépôt de données connecté [g]" accesskey="g"><span>Élément Wikidata</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Outils de la page"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Apparence"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Apparence</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">déplacer vers la barre latérale</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">masquer</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">Un article de Wikipédia, l'encyclopédie libre.</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="fr" dir="ltr"><div class="bandeau-container metadata homonymie hatnote"><div class="bandeau-cell bandeau-icone" style="display:table-cell;padding-right:0.5em"><span class="noviewer" typeof="mw:File"><a href="/wiki/Aide:Homonymie" title="Aide:Homonymie"><img alt="Page d’aide sur l’homonymie" src="//upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Logo_disambig.svg/20px-Logo_disambig.svg.png" decoding="async" width="20" height="15" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Logo_disambig.svg/30px-Logo_disambig.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/a/a9/Logo_disambig.svg/40px-Logo_disambig.svg.png 2x" data-file-width="512" data-file-height="375" /></a></span></div><div class="bandeau-cell" style="display:table-cell;padding-right:0.5em"> <p>Pour les articles homonymes, voir <a href="/wiki/Lemme" class="mw-disambig" title="Lemme">Lemme</a>. </p> </div></div> <div class="bandeau-container metadata bandeau-article bandeau-niveau-ebauche"><div class="bandeau-cell bandeau-icone" style="display:table-cell;padding-right:0.5em"><span class="noviewer" typeof="mw:File"><a href="/wiki/Fichier:Racine_carr%C3%A9e_bleue.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Racine_carr%C3%A9e_bleue.svg/35px-Racine_carr%C3%A9e_bleue.svg.png" decoding="async" width="35" height="35" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Racine_carr%C3%A9e_bleue.svg/53px-Racine_carr%C3%A9e_bleue.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Racine_carr%C3%A9e_bleue.svg/70px-Racine_carr%C3%A9e_bleue.svg.png 2x" data-file-width="128" data-file-height="128" /></a></span></div><div class="bandeau-cell" style="display:table-cell;padding-right:0.5em"> <p><strong class="bandeau-titre">Cet article est une <a href="/wiki/Aide:%C3%89bauche" title="Aide:Ébauche">ébauche</a> concernant les <a href="/wiki/Math%C3%A9matiques" title="Mathématiques">mathématiques</a>.</strong> </p><p>Vous pouvez partager vos connaissances en l’améliorant (<b><a href="/wiki/Aide:Comment_modifier_une_page" title="Aide:Comment modifier une page">comment ?</a></b>) selon les recommandations des <a href="/wiki/Projet:Accueil" title="Projet:Accueil">projets correspondants</a>. </p> </div></div> <p>Un <b>lemme</b>, en <a href="/wiki/Math%C3%A9matiques" title="Mathématiques">mathématiques</a> et en <a href="/wiki/Logique_math%C3%A9matique" title="Logique mathématique">logique mathématique</a>, est un résultat intermédiaire sur lequel on s'appuie pour conduire la <a href="/wiki/D%C3%A9monstration_(logique_et_math%C3%A9matique)" class="mw-redirect" title="Démonstration (logique et mathématique)">démonstration</a> d'un <a href="/wiki/Th%C3%A9or%C3%A8me" title="Théorème">théorème</a> plus important. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Étymologie"><span id=".C3.89tymologie"></span>Étymologie</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&veaction=edit&section=1" title="Modifier la section : Étymologie" class="mw-editsection-visualeditor"><span>modifier</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=edit&section=1" title="Modifier le code source de la section : Étymologie"><span>modifier le code</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Dans l'Antiquité grecque, <i>lemme</i> (en <a href="/wiki/Grec_ancien" title="Grec ancien">grec ancien</a> : <span class="lang-grc" lang="grc">λῆμμα</span>) était un terme de <a href="/wiki/Logique" title="Logique">logique</a> : il désignait la <a href="/wiki/Pr%C3%A9misse" title="Prémisse">majeure</a> du <a href="/wiki/Syllogisme" title="Syllogisme">syllogisme</a>, c'est-à-dire la première assertion. Dans la dialectique grecque, le lemme, le prolemme et l'<a href="/wiki/%C3%89piphore" title="Épiphore">épiphore</a> sont les trois parties de l'argument. </p><p>Par extension, <i>lemme</i> désigne en mathématiques l'un des arguments de la preuve sans en être le fondement puis, plus généralement, un résultat intermédiaire utile à la démonstration d'un théorème<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite_crochet">[</span>1<span class="cite_crochet">]</span></a></sup>. </p> <div class="mw-heading mw-heading2"><h2 id="Principe">Principe</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&veaction=edit&section=2" title="Modifier la section : Principe" class="mw-editsection-visualeditor"><span>modifier</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=edit&section=2" title="Modifier le code source de la section : Principe"><span>modifier le code</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>En effet, la méthode de démonstration d'un théorème est souvent la suivante : </p> <ol><li>on veut démontrer le théorème <i><b>T</b></i> à partir d'une certaine liste d'<a href="/wiki/Axiome" title="Axiome">axiomes</a> et d'autres résultats déjà démontrés mais cela n'a pas l'air évident au premier abord,</li> <li>mais on se dit que, si on savait <i><b>L</b></i> vrai (<i><b>L</b></i> étant alors une autre assertion dénommée <i>lemme</i>), on pourrait conclure immédiatement étant donné les règles de logique admises,</li> <li>on pose alors <i><b>L</b></i> comme le résultat à démontrer et on lui applique une méthode de démonstration de théorème,</li> <li>une fois <i><b>L</b></i> démontré, on en déduit <i><b>T</b></i>.</li></ol> <p>Ce principe est notamment utilisé par les <a href="/wiki/Logiciel" title="Logiciel">logiciels</a> appelés <a href="/wiki/Assistant_de_preuve" title="Assistant de preuve">assistants de preuve</a> tels <a href="/wiki/Coq_(logiciel)" title="Coq (logiciel)">Coq</a> ou <a href="/wiki/Prototype_Verification_System" title="Prototype Verification System">PVS</a>. </p><p>Certains lemmes démontrés deviennent plus célèbres que le théorème pour lequel ils ont été créés et restent connus sous le nom <i>« lemmes de X »</i><sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite_crochet">[</span>2<span class="cite_crochet">]</span></a></sup><sup class="reference cite_virgule">,</sup><sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite_crochet">[</span>3<span class="cite_crochet">]</span></a></sup><sup class="reference cite_virgule">,</sup><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite_crochet">[</span>4<span class="cite_crochet">]</span></a></sup> bien que jouant habituellement un rôle de théorème. </p> <div class="mw-heading mw-heading2"><h2 id="Lemmes_célèbres"><span id="Lemmes_c.C3.A9l.C3.A8bres"></span>Lemmes célèbres</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&veaction=edit&section=3" title="Modifier la section : Lemmes célèbres" class="mw-editsection-visualeditor"><span>modifier</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=edit&section=3" title="Modifier le code source de la section : Lemmes célèbres"><span>modifier le code</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="bandeau-container bandeau-section metadata bandeau-niveau-information"><div class="bandeau-cell bandeau-icone-css loupe">Article détaillé : <a href="/wiki/Liste_de_lemmes" title="Liste de lemmes">Liste de lemmes</a>.</div></div> <ul><li><a href="/wiki/Lemme_de_Zorn" title="Lemme de Zorn">lemme de Zorn</a> : célèbre pour être équivalent à l'<a href="/wiki/Axiome_du_choix" title="Axiome du choix">axiome du choix</a> dans la <a href="/wiki/Th%C3%A9orie_des_ensembles" title="Théorie des ensembles">théorie des ensembles ZF</a> — joue donc aussi bien le rôle d'un théorème conséquence de cet <a href="/wiki/Axiome" title="Axiome">axiome</a> que celui d'une reformulation de l'axiome (donc d'un axiome) ;</li> <li><a href="/wiki/Lemme_de_l%27%C3%A9toile" title="Lemme de l'étoile">lemme de l'étoile</a> : théorème de la théorie des <a href="/wiki/Langage_formel" title="Langage formel">langages formels</a>, devenu plus célèbre que le théorème de l'étoile ;</li> <li><a href="/wiki/Lemme_des_bergers" title="Lemme des bergers">lemme des bergers</a> ;</li> <li><a href="/wiki/Lemme_d%27Euclide" title="Lemme d'Euclide">lemme d'Euclide</a> ;</li> <li><a href="/wiki/Lemme_de_Gauss_(th%C3%A9orie_des_nombres)" title="Lemme de Gauss (théorie des nombres)">lemme de Gauss</a> (généralisation du lemme d'Euclide) ;</li> <li><a href="/wiki/Lemme_de_Jordan" title="Lemme de Jordan">lemme de Jordan</a> ;</li> <li><a href="/wiki/S%C3%A9rie_enti%C3%A8re#Rayon_de_convergence" title="Série entière">lemme d'Abel</a> ;</li> <li>lemme de Shephard (<a href="/wiki/Th%C3%A9orie_du_consommateur_(micro%C3%A9conomie)" title="Théorie du consommateur (microéconomie)">théorie du consommateur</a>) : la dérivée de la fonction de coût par rapport au prix donne la fonction de demande conditionnelle ou demande compensée ;</li> <li><a href="/wiki/Lemme_de_Hotelling" title="Lemme de Hotelling">lemme de Hotelling</a> ;</li> <li><a href="/wiki/Lemme_de_Goursat_(analyse_complexe)" title="Lemme de Goursat (analyse complexe)">lemme de Goursat</a> ;</li> <li><a href="/wiki/Lemme_d%27It%C5%8D" title="Lemme d'Itō">lemme d'Itō</a> ;</li> <li><a href="/wiki/Lemme_de_Yoneda" title="Lemme de Yoneda">lemme de Yoneda</a>.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Voir_aussi">Voir aussi</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&veaction=edit&section=4" title="Modifier la section : Voir aussi" class="mw-editsection-visualeditor"><span>modifier</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=edit&section=4" title="Modifier le code source de la section : Voir aussi"><span>modifier le code</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Th%C3%A9or%C3%A8me" title="Théorème">Théorème</a></li></ul> <ul><li><a href="/wiki/Corollaire_(math%C3%A9matiques)" title="Corollaire (mathématiques)">Corollaire</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Références"><span id="R.C3.A9f.C3.A9rences"></span>Références</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&veaction=edit&section=5" title="Modifier la section : Références" class="mw-editsection-visualeditor"><span>modifier</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=Lemme_(math%C3%A9matiques)&action=edit&section=5" title="Modifier le code source de la section : Références"><span>modifier le code</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="references-small decimal" style=""><div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink noprint"><a href="#cite_ref-1">↑</a> </span><span class="reference-text"><span class="ouvrage" id="Hauchecorne2003"><span class="ouvrage" id="Bertrand_Hauchecorne2003">Bertrand Hauchecorne, <cite class="italique">Les mots et les maths. Dictionnaire historique et étymologique du vocabulaire mathématique.</cite>, Paris, Ellipses, <time>2003</time>, 223 <abbr class="abbr" title="pages">p.</abbr> <small style="line-height:1em;">(<a href="/wiki/International_Standard_Book_Number" title="International Standard Book Number">ISBN</a> <a href="/wiki/Sp%C3%A9cial:Ouvrages_de_r%C3%A9f%C3%A9rence/978-2-7298-1528-8" title="Spécial:Ouvrages de référence/978-2-7298-1528-8"><span class="nowrap">978-2-7298-1528-8</span></a> et <a href="/wiki/Sp%C3%A9cial:Ouvrages_de_r%C3%A9f%C3%A9rence/2-7298-1528-7" title="Spécial:Ouvrages de référence/2-7298-1528-7"><span class="nowrap">2-7298-1528-7</span></a>)</small><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Les+mots+et+les+maths.+Dictionnaire+historique+et+%C3%A9tymologique+du+vocabulaire+math%C3%A9matique.&rft.place=Paris&rft.pub=Ellipses&rft.aulast=Hauchecorne&rft.aufirst=Bertrand&rft.date=2003&rft.tpages=223&rft.isbn=978-2-7298-1528-8&rfr_id=info%3Asid%2Ffr.wikipedia.org%3ALemme+%28math%C3%A9matiques%29"></span></span></span>.</span> </li> <li id="cite_note-2"><span class="mw-cite-backlink noprint"><a href="#cite_ref-2">↑</a> </span><span class="reference-text"><span class="ouvrage" id="1909">« <a rel="nofollow" class="external text" href="https://gallica.bnf.fr/ark:/12148/bpt6k2025807/texteBrut"><cite style="font-style:normal;">Encyclopédie des sciences mathématiques pures et appliquées. Tome II. Premier volume, Fonctions de variables réelles</cite></a> », sur <span class="italique">bnf.fr</span>, <time>1909</time> <small style="line-height:1em;">(consulté le <time class="nowrap" datetime="2023-11-13" data-sort-value="2023-11-13">13 novembre 2023</time>)</small></span>.</span> </li> <li id="cite_note-3"><span class="mw-cite-backlink noprint"><a href="#cite_ref-3">↑</a> </span><span class="reference-text"><span class="ouvrage" id="Christophe1997"><span class="ouvrage" id="Charlier,_Christophe1997">Charlier, Christophe, « <cite style="font-style:normal">Effet irréversibilité et information endogène. Application à la dissémination d'organismes génétiquement modifiés.</cite> », <i><a href="/wiki/Revue_%C3%A9conomique" title="Revue économique">Revue économique</a></i>, <a href="/wiki/Pers%C3%A9e_(portail)" title="Persée (portail)">Persée</a>, <abbr class="abbr" title="volume">vol.</abbr> 48, <abbr class="abbr" title="numéro">n<sup>o</sup></abbr> 1,‎ <time>1997</time>, <abbr class="abbr" title="pages">p.</abbr> <span class="nowrap">93–105</span> <small style="line-height:1em;">(<a href="/wiki/Digital_Object_Identifier" title="Digital Object Identifier">DOI</a> <span class="plainlinks noarchive nowrap"><a rel="nofollow" class="external text" href="https://dx.doi.org/10.3406/reco.1997.409865">10.3406/reco.1997.409865</a></span>, <a rel="nofollow" class="external text" href="https://www.persee.fr/doc/reco_0035-2764_1997_num_48_1_409865">lire en ligne</a>, consulté le <time class="nowrap" datetime="2023-11-13" data-sort-value="2023-11-13">13 novembre 2023</time>)</small><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.atitle=Effet+irr%C3%A9versibilit%C3%A9+et+information+endog%C3%A8ne.+Application+%C3%A0+la+diss%C3%A9mination+d%27organismes+g%C3%A9n%C3%A9tiquement+modifi%C3%A9s.&rft.jtitle=Revue+%C3%A9conomique&rft.issue=1&rft.aulast=Christophe&rft.aufirst=Charlier%2C&rft.date=1997&rft.volume=48&rft.pages=93%E2%80%93105&rft_id=info%3Adoi%2F10.3406%2Freco.1997.409865&rfr_id=info%3Asid%2Ffr.wikipedia.org%3ALemme+%28math%C3%A9matiques%29"></span></span></span>.</span> </li> <li id="cite_note-4"><span class="mw-cite-backlink noprint"><a href="#cite_ref-4">↑</a> </span><span class="reference-text">Comme le lemme de <a href="/w/index.php?title=X._Freixas&action=edit&redlink=1" class="new" title="X. Freixas (page inexistante)">X. Freixas</a> <a href="https://es.wikipedia.org/wiki/Xavier_Freixas" class="extiw" title="es:Xavier Freixas"><span class="indicateur-langue" title="Article en espagnol : « Xavier Freixas »">(es)</span></a> ?</span> </li> </ol></div> </div> <ul id="bandeau-portail" class="bandeau-portail"><li><span class="bandeau-portail-element"><span class="bandeau-portail-icone"><span class="noviewer skin-invert-image" typeof="mw:File"><a href="/wiki/Portail:Math%C3%A9matiques" title="Portail des mathématiques"><img alt="icône décorative" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Racine_carr%C3%A9e_bleue.svg/24px-Racine_carr%C3%A9e_bleue.svg.png" decoding="async" width="24" height="24" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Racine_carr%C3%A9e_bleue.svg/36px-Racine_carr%C3%A9e_bleue.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Racine_carr%C3%A9e_bleue.svg/48px-Racine_carr%C3%A9e_bleue.svg.png 2x" data-file-width="128" data-file-height="128" /></a></span></span> <span class="bandeau-portail-texte"><a href="/wiki/Portail:Math%C3%A9matiques" title="Portail:Mathématiques">Portail des mathématiques</a></span> </span></li> </ul>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1&useformat=desktop" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Ce document provient de « <a dir="ltr" href="https://fr.wikipedia.org/w/index.php?title=Lemme_(mathématiques)&oldid=217707308">https://fr.wikipedia.org/w/index.php?title=Lemme_(mathématiques)&oldid=217707308</a> ».</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Cat%C3%A9gorie:Accueil" title="Catégorie:Accueil">Catégories</a> : <ul><li><a href="/wiki/Cat%C3%A9gorie:Lemme_de_math%C3%A9matiques" title="Catégorie:Lemme de mathématiques">Lemme de mathématiques</a></li><li><a href="/wiki/Cat%C3%A9gorie:Logique_math%C3%A9matique" title="Catégorie:Logique mathématique">Logique mathématique</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Catégories cachées : <ul><li><a href="/wiki/Cat%C3%A9gorie:Article_contenant_un_appel_%C3%A0_traduction_en_espagnol" title="Catégorie:Article contenant un appel à traduction en espagnol">Article contenant un appel à traduction en espagnol</a></li><li><a href="/wiki/Cat%C3%A9gorie:Wikip%C3%A9dia:%C3%A9bauche_math%C3%A9matiques" title="Catégorie:Wikipédia:ébauche mathématiques">Wikipédia:ébauche mathématiques</a></li><li><a href="/wiki/Cat%C3%A9gorie:Portail:Math%C3%A9matiques/Articles_li%C3%A9s" title="Catégorie:Portail:Mathématiques/Articles liés">Portail:Mathématiques/Articles liés</a></li><li><a href="/wiki/Cat%C3%A9gorie:Portail:Sciences/Articles_li%C3%A9s" title="Catégorie:Portail:Sciences/Articles liés">Portail:Sciences/Articles liés</a></li><li><a href="/wiki/Cat%C3%A9gorie:Projet:Math%C3%A9matiques/Articles" title="Catégorie:Projet:Mathématiques/Articles">Projet:Mathématiques/Articles</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> La dernière modification de cette page a été faite le 15 août 2024 à 20:05.</li> <li id="footer-info-copyright"><span style="white-space: normal"><a href="/wiki/Wikip%C3%A9dia:Citation_et_r%C3%A9utilisation_du_contenu_de_Wikip%C3%A9dia" title="Wikipédia:Citation et réutilisation du contenu de Wikipédia">Droit d'auteur</a> : les textes sont disponibles sous <a rel="nofollow" class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.fr">licence Creative Commons attribution, partage dans les mêmes conditions</a> ; d’autres conditions peuvent s’appliquer. Voyez les <a class="external text" href="https://foundation.wikimedia.org/wiki/Policy:Terms_of_Use/fr">conditions d’utilisation</a> pour plus de détails, ainsi que les <a href="/wiki/Wikip%C3%A9dia:Cr%C3%A9dits_graphiques" title="Wikipédia:Crédits graphiques">crédits graphiques</a>. En cas de réutilisation des textes de cette page, voyez <a href="/wiki/Sp%C3%A9cial:Citer/Lemme_(math%C3%A9matiques)" title="Spécial:Citer/Lemme (mathématiques)">comment citer les auteurs et mentionner la licence</a>.<br /> Wikipedia® est une marque déposée de la <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, organisation de bienfaisance régie par le paragraphe <a href="/wiki/501c" title="501c">501(c)(3)</a> du code fiscal des États-Unis.</span><br /></li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy/fr">Politique de confidentialité</a></li> <li id="footer-places-about"><a href="/wiki/Wikip%C3%A9dia:%C3%80_propos_de_Wikip%C3%A9dia">À propos de Wikipédia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikip%C3%A9dia:Avertissements_g%C3%A9n%C3%A9raux">Avertissements</a></li> <li id="footer-places-contact"><a href="//fr.wikipedia.org/wiki/Wikipédia:Contact">Contact</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code de conduite</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Développeurs</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/fr.wikipedia.org">Statistiques</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Déclaration sur les témoins (cookies)</a></li> <li id="footer-places-mobileview"><a href="//fr.m.wikipedia.org/w/index.php?title=Lemme_(math%C3%A9matiques)&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Version mobile</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-59bbd5969d-nzrbq","wgBackendResponseTime":155,"wgPageParseReport":{"limitreport":{"cputime":"0.167","walltime":"0.244","ppvisitednodes":{"value":581,"limit":1000000},"postexpandincludesize":{"value":13425,"limit":2097152},"templateargumentsize":{"value":342,"limit":2097152},"expansiondepth":{"value":12,"limit":100},"expensivefunctioncount":{"value":2,"limit":500},"unstrip-depth":{"value":0,"limit":20},"unstrip-size":{"value":4952,"limit":5000000},"entityaccesscount":{"value":1,"limit":400},"timingprofile":["100.00% 217.425 1 -total"," 26.92% 58.526 1 Modèle:Références"," 20.77% 45.158 1 Modèle:Ébauche"," 20.05% 43.603 1 Modèle:Portail"," 15.95% 34.688 1 Modèle:Voir_homonymes"," 14.98% 32.565 1 Modèle:Méta_bandeau_de_note"," 14.61% 31.761 1 Modèle:Ouvrage"," 13.98% 30.397 1 Modèle:Méta_bandeau"," 11.32% 24.610 1 Modèle:Lang-grc"," 10.56% 22.955 1 Modèle:Langue_avec_nom"]},"scribunto":{"limitreport-timeusage":{"value":"0.096","limit":"10.000"},"limitreport-memusage":{"value":6356405,"limit":52428800}},"cachereport":{"origin":"mw-web.codfw.main-76c6b8f495-swrqx","timestamp":"20241128142758","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Lemme (math\u00e9matiques)","url":"https:\/\/fr.wikipedia.org\/wiki\/Lemme_(math%C3%A9matiques)","sameAs":"http:\/\/www.wikidata.org\/entity\/Q207505","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q207505","author":{"@type":"Organization","name":"Contributeurs aux projets Wikimedia"},"publisher":{"@type":"Organization","name":"Fondation Wikimedia, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2004-08-18T17:49:48Z","dateModified":"2024-08-15T19:05:55Z","headline":"th\u00e9or\u00e8me utile pour d\u00e9montrer d'autres th\u00e9or\u00e8mes"}</script> </body> </html>