-\newtheorem{Def}{\underline{Définition}}
-\newtheorem{Lemma}{\underline{Lemme}}
-\newtheorem{Theo}{\underline{Théorème}}
+\newtheorem{Def}{\underline{Definition}}
+\newtheorem{Lemma}{\underline{Lemma}}
+\newtheorem{Theo}{\underline{Theorem}}
% \theoremheaderfont{\sc}
% \theorembodyfont{\upshape}
% \theoremstyle{nonumberplain}
% \theoremseparator{}
% \theoremsymbol{\rule{1ex}{1ex}}
% \theoremheaderfont{\sc}
% \theorembodyfont{\upshape}
% \theoremstyle{nonumberplain}
% \theoremseparator{}
% \theoremsymbol{\rule{1ex}{1ex}}
\newcommand{\vectornorm}[1]{\ensuremath{\left|\left|#1\right|\right|_2}}
%\newcommand{\ie}{\textit{i.e.}}
\newcommand{\vectornorm}[1]{\ensuremath{\left|\left|#1\right|\right|_2}}
%\newcommand{\ie}{\textit{i.e.}}