<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">%% 
%%  Ein Beispiel der DANTE-Edition
%%  Mathematiksatz mit LaTeX
%%  3. Auflage
%%  Beispiel 09-22-1 auf Seite 204.
%%  Copyright (C) 2018 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
%% 
%% 
\documentclass[10pt]{exaartplain}
\pagestyle{empty}
\setlength\textwidth{170.40707pt}
\AtBeginDocument{\setlength\parindent{0pt}}
%StartShownPreambleCommands
\usepackage{nicematrix}
%StopShownPreambleCommands
\begin{document}
$\left[\begin{NiceArray}{CCCC|C}
a_1  &amp; ? &amp; \Cdots &amp; ? &amp; ?  \\
0    &amp;   &amp; \Ddots &amp; \Vdots &amp; \Vdots\\
\Vdots &amp; \Ddots &amp; \Ddots &amp; ? \\
0 &amp; \Cdots &amp; 0 &amp; a_n     &amp; ? \\
\end{NiceArray}\right]$
\par\bigskip
$\begin{pNiceArrayC}{*6C|C}[nullify-dots,
  code-for-last-col={\small}]
1 &amp; 1 &amp; 1 &amp;\Cdots &amp; &amp; 1 &amp; 0 &amp; \\
0 &amp; 1 &amp; 0 &amp;\Cdots &amp; &amp; 0 &amp;&amp; L_2 \gets L_2-L_1 \\
0 &amp; 0 &amp; 1 &amp;\Ddots &amp; &amp; \Vdots &amp; &amp; L_3 \gets L_3-L_1 \\
  &amp;   &amp;   &amp;\Ddots &amp; &amp;&amp; \Vdots &amp; \Vdots \\
\Vdots&amp;   &amp; &amp;\Ddots &amp; &amp; 0 &amp; \\
0 &amp; &amp; &amp;\Cdots &amp; 0 &amp; 1 &amp; 0 &amp; L_n \gets L_n-L_1
\end{pNiceArrayC}$
\end{document}
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