%
% Patch to implement French uses with a \book section at level -2.
%
\makeatletter
% Translate \bookname.
\def\bookname{Livre}%
% If \book and \part are used, reset \part at \book.
\@ifundefined{c@book}{}{%
  \@ifundefined{c@part}{}{\@addtoreset{part}{book}}}%
% If \book is not used, stay with the old code for hyperref.
\@ifundefined{theHbook}{%
  \@ifundefined{theHchapter}{}%
    {\renewcommand{\theHchapter}{\arabic{part}.\arabic{chapter}}}%
}{%
% When \part is reset at \book, hyperref needs the following code.
  \@ifundefined{theHpart}{}%
    {\renewcommand{\theHpart}{\arabic{book}.\arabic{part}}}%
  \@ifundefined{theHchapter}{}%
    {\renewcommand{\theHchapter}{\arabic{book}.\arabic{part}.\arabic{chapter}}}%
}%
\makeatother