%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  1. Auflage
%% 
%%  Beispiel 12-01-1 auf Seite 613.
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%%  Copyright (C) 2011 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.
%% 
%% 
%% ==== 
% Show page(s) 1
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\documentclass[]{exaarticle2}
\pagestyle{empty}
\setlength\textwidth{190.324pt}
\StartShownPreambleCommands
\usepackage{fontspec}
\StopShownPreambleCommands
\begin{document}
\fontspec{Linux Libertine O}
1/2, 4/7, 33/40 $\rightarrow$
\addfontfeature{Fractions=On}
1/2, 4/7, 33/40
%\addfontfeature{Fractions=Alternate}
%1/2, 4/7, 33/40
\end{document}