%%
%% The LaTeX Companion, 3ed
%%
%% Example 11-3-6 on page II-156 in "amsmath, mathtools, cases --- Some case environments".
%%
%% 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{tlc3examargin}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{183.0pt}

%StartShownPreambleCommands
\usepackage{mathtools,bm}
%StopShownPreambleCommands

\begin{document}
\begin{equation*} \begin{rcases}
   \bm{B}' = -c\nabla\times\bm{E}            \\
   \bm{E}' =  c\nabla\times\bm{B} - 4\pi\bm{J}\,
 \end{rcases} \enspace \text{Maxwell}
\end{equation*}
\end{document}