%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  1. Auflage
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%%  Beispiel 09-08-10 auf Seite 478.
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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[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{142.324pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\usepackage{amsmath,color,cancel}
\newcommand\hcancel[2][black]{%
  \setbox0=\hbox{#2}%
    \rlap{\raisebox{.45\ht0}{%
      \textcolor{#1}{\rule{\wd0}{1pt}}}}#2}
\StopShownPreambleCommands
\begin{document}
$\cancel{3}\qquad
    f(x)=\dfrac{\left(x^2+1\right)
    \cancel{(x-1)}}{\cancel{(x-1)}(x+1)}$\\[0.5cm]
$\bcancel{3}\qquad\bcancel{1234567}$\\[0.5cm]
\renewcommand*{\CancelColor}{\color{cyan}}
$\xcancel{3}\qquad\xcancel{1234567}$\\[0.5cm]
$\hcancel{3}\qquad\hcancel[red]{1234567}$
\end{document}