%% 
%%  Der Mathematiksatz mit LaTeX, 1. Auflage 2009
%% 
%%  Example 4-20-4 on page 72.
%% 
%%  Copyright (C) 2009 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}
\setlength\fboxsep{0pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\newcommand*\Frac[2]{\displaystyle\frac{#1}{#2}}
\StopShownPreambleCommands
\begin{document}
links\rule{1cm}{.5pt}\fbox{$\Frac{A}{B}$}
\fbox{\raisebox{0pt}[0pt][0pt]{$\Frac{C}{D}$}}\fbox{\raisebox{0pt}[0pt][1cm]{$\Frac{E}{F}$}}
\fbox{\raisebox{0pt}[1cm][0pt]{$\Frac{G}{H}$}}\fbox{\raisebox{0pt}[1cm][1cm]{$\Frac{I}{J}$}}
\fbox{\raisebox{1cm}[0pt][0pt]{$\Frac{K}{L}$}}
\fbox{\raisebox{-1cm}{$\Frac{M}{N}$}}\rule{1cm}{.5pt}rechts
\end{document}