%%
%% The LaTeX Companion, 2ed
%%
%% Example 8-3-28 on page 510.
%%
%% Copyright (C) 2004 Frank Mittelbach, Michel Goossens,
%%    Johannes Braams, David Carlisle, and Chris Rowley
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3
%% of this license or (at your option) any later version.
%%
%% See http://www.latex-project.org/lppl.txt for details.
%%

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{111.0pt}

\StartShownPreambleCommands
\usepackage[english,french]{babel}  \usepackage{dcolumn}
\newcolumntype{d}{D{,}{\decimalsep}{-1}} % align at explicit `,'
                                         % but output \decimalsep 
\StopShownPreambleCommands
\begin{document}
\begin{tabular}{|d|}  \hline
            12,34567  \\ % recognized but not corectly formatted
    \nombre{12,34567} \\ % not recognized but corectly formatted
 \nombre[,]{12,34567} \\
 \nombre[,]{9876543,21} \\ \hline
\end{tabular}
\par\vspace{1cm}   \selectlanguage{english} % change language
\begin{tabular}{|d|}     \hline
 \nombre[,]{12,34567} \\ \nombre[,]{9876543,21} \\ \hline
\end{tabular}
\end{document}