%%
%% The LaTeX Companion, 3ed
%%
%% Example 11-2-24 on page II-144 in "Vertical space in and around displays".
%%
%% 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{231.0pt}

%StartShownPreambleCommands
\usepackage{amsmath}
%StopShownPreambleCommands

\begin{document}
We now have the following:
\[  X = a \qquad  a = c \]
and thus we have
\begin{equation}  X = c \end{equation}
And now we do not get much space
around the display!
\end{document}
