%% Théorèmes
\newtheorem{theoreme}{Théorème}[section]
\newtheorem{corollaire}[theoreme]{Corollaire}
\newtheorem{lemme}[theoreme]{Lemme}

\theoremstyle{definition}
\newtheorem{fdefinition}[theoreme]{Définition}
    
\theoremstyle{example}
\newtheorem{exemple}[theoreme]{Exemple}
\newtheorem{exercice}[theoreme]{Exercice}

\newenvironment{preuve}{\begin{proof}[Preuve]}{\end{proof}}