%% 
%%  \protect \LaTeX  -Referenz, 1. Auf"|lage 2007
%% 
%%  Example 7-6-2 on page 114.
%% 
%%  Copyright (C) 2007 Herbert Voss
%% 
%%  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{355.65944pt}
\StartShownPreambleCommands
\usepackage{amsmath,setspace}
\newcommand*\fBox[2][0.125]{\framebox[#1\columnwidth]{#2}}
\setstretch{0.5}
\StopShownPreambleCommands
\begin{document}
\begin{align}
\fBox{align} &= \fBox{x} & \fBox{x}&= \fBox{x}
\end{align}
%
\begin{alignat}{2}
\fBox{alignat} &= \fBox{x} & \fBox{x} &= \fBox{x}
\end{alignat}
%
\begin{flalign}
\fBox{flalign} &= \fBox{x} & \fBox{x} &= \fBox{x}
\end{flalign}
\end{document}