% On définit quelques macros de plain TeX pour que LaTeX ne se pleigne pas trop
\catcode`@=11

\let\over\@@over % LaTeX garde la primitive sous le nom \@@over

% Les environnement math aligné
\def\openup{\afterassignment\@penup\dimen@=}
\def\ialign{\everycr{}\tabskip\z@skip\halign} % initialized \halign
\def\@penup{\advance\lineskip\dimen@
  \advance\baselineskip\dimen@
  \advance\lineskiplimit\dimen@}
\def\eqalign#1{\null\,\vcenter{\openup\jot\m@th
  \ialign{\strut\hfil$\displaystyle{##}$&$\displaystyle{{}##}$\hfil
      \crcr#1\crcr}}\,}
\newif\ifdt@p
\def\displ@y{\global\dt@ptrue\openup\jot\m@th
  \everycr{\noalign{\ifdt@p \global\dt@pfalse \ifdim\prevdepth>-1000\p@
      \vskip-\lineskiplimit \vskip\normallineskiplimit \fi
      \else \penalty\interdisplaylinepenalty \fi}}}
\def\@lign{\tabskip\z@skip\everycr{}} % restore inside \displ@y
\def\displaylines#1{\displ@y \tabskip\z@skip
  \halign{\hbox to\displaywidth{$\@lign\hfil\displaystyle##\hfil$}\crcr
    #1\crcr}}
\newskip\@plaincentering
\@plaincentering=0pt plus 1000pt minus 1000pt
\def\eqalignno#1{\displ@y \tabskip\@plaincentering
  \halign to\displaywidth{\hfil$\@lign\displaystyle{##}$\tabskip\z@skip
    &$\@lign\displaystyle{{}##}$\hfil\tabskip\@plaincentering
    &\llap{$\@lign##$}\tabskip\z@skip\crcr
    #1\crcr}}
\def\leqalignno#1{\displ@y \tabskip\@plaincentering
  \halign to\displaywidth{\hfil$\@lign\displaystyle{##}$\tabskip\z@skip
    &$\@lign\displaystyle{{}##}$\hfil\tabskip\@plaincentering
    &\kern-\displaywidth\rlap{$\@lign##$}\tabskip\displaywidth\crcr
    #1\crcr}}
\def\cases#1{\left\{\,\vcenter{\normalbaselines\m@th
    \ialign{$##\hfil$&\quad##\hfil\crcr#1\crcr}}\right.}
\def\matrix#1{\null\,\vcenter{\normalbaselines\m@th
    \ialign{\hfil$##$\hfil&&\quad\hfil$##$\hfil\crcr
      \mathstrut\crcr\noalign{\kern-\baselineskip}
      #1\crcr\mathstrut\crcr\noalign{\kern-\baselineskip}}}\,}
\def\pmatrix#1{\left(\matrix{#1}\right)}
\def\raggedcenter{\leftskip=0pt plus4em \rightskip=\leftskip
\parfillskip=0pt \spaceskip=.3333em \xspaceskip=.5em
\pretolerance=9999 \tolerance=9999 \parindent=0pt
\hyphenpenalty=9999 \exhyphenpenalty=9999 }

% Les items
\def\hang{\hangindent\parindent}
\def\textindent#1{\indent\llap{#1\enspace}\ignorespaces}
\def\Item{\par\hang\textindent}
\def\Itemitem{\par\indent \hangindent2\parindent \textindent}
\def\narrower{\advance\leftskip\parindent
  \advance\rightskip\parindent}

% Protection
\AtBeginDocument{\aaaa}
\long\def\aaaa#1\finliste{\begin{frame}{}\relax\vfill
  \font\auteurfonte=cmr12 at 50pt % auteur
  \centerline{\auteurfonte Ici se trouve l'affiche. Dommage que vous
  ne pouvez pas la voir!}
  \vfill
  \vfill
  \end{frame}
}



% Symboles superposés
\def\buildrel#1\over#2{\mathrel{\mathop{\kern\z@#2}\limits^{#1}}}



\catcode`@=12
