%% 
%%  Der Mathematiksatz mit LaTeX, 1. Auflage 2009
%% 
%%  Example 8-1-8 on page 161.
%% 
%%  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[]{ttctminimal}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{355.65944pt}
\AtBeginDocument{\setlength\parindent{0pt}\ttfamily}
\StartShownPreambleCommands

\StopShownPreambleCommands
\begin{document}
\global\muskip1=30mu plus20mu minus10mu
\global\muskip3=40mu plus 1fil% 1fil -> dynamische Länge
$A\mskip\muskip1 B\mskip\muskip3 C$
\end{document}