\documentclass[10pt,a4paper]{book}
\usepackage{luahyphenrules}%
\usepackage{french}%
\let\PEx\pointexclamation%
%
\usepackage{hyperref}
\usepackage{xurl}
%
\title{ECM}
\author{Francis Gernet}
\begin{document}
\HyphenRules{french} % pour les césures en français
%
\part{Partie 1}
\include{elek-a}
%
\include{elek-b}
\end{document}
