%%
%% The LaTeX Companion, 3ed
%%
%% Example 6-2-3 on page I-438 in "Examples of preamble specifiers".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{183.0pt}
%StartShownPreambleCommands
\usepackage{array} \setlength\overfullrule{5pt}
%StopShownPreambleCommands

\begin{document}
\begin{tabular}{|r|wr{13mm}|Wr{15mm}|}
  flexible (r)& fixed (w)   & fixed (W)  \\
  123         & 123         & 123        \\
  123456789   & 123456789   & 123456789  \\
  ab cd ef gh & ab cd ef gh & ab cd ef gh\\
\end{tabular}
\end{document}