%% 
%%  Der Mathematiksatz mit LaTeX, 1. Auflage 2009
%% 
%%  Example 8-1-2 on page 158.
%% 
%%  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{194.59192pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands

\StopShownPreambleCommands
\begin{document}
\[
y = \left\{%
 \begin{array}{ll}
   x^2+2x  &\textrm{if }x<0,\\
   x^3     &\textrm{if }0\le x<1,\\
   x^2+x   &\textrm{if }1\le x<2,\\
   x^3-x^2 &\textrm{if }2\le x.
 \end{array}%
\right.
\]
\end{document}