%%
%% The LaTeX Companion, 3ed
%%
%% Example 11-7-19 on page II-206 in "resizegather --- Downscaling an equation".
%%
%% 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{127.0pt}
% Shorten the vertical size of the example ...
\AtBeginDocument{%
\setlength\abovedisplayskip{.2\abovedisplayskip}%
\setlength\belowdisplayskip{.2\belowdisplayskip}%
}
%StartShownPreambleCommands
\usepackage{amsmath}
%StopShownPreambleCommands
\begin{document}
\begin{gather} a+b+c+d+e+f+g = X \\
a+b+c+d+e+f+g+h = Y \end{gather}
\end{document}
