<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">% \subsubsection{Proofs}
% \DescribeEnv{proof}{A mathematical proof environment.}
%    \begin{macrocode}
%&lt;*classXimera&gt;
\renewcommand{\qedsymbol}{$\blacksquare$}
\renewenvironment{proof}[1][\proofname]
  {\begin{trivlist}\item[\hskip \labelsep \itshape \bfseries #1{}\hspace{2ex}]}
{\qed\end{trivlist}}
%&lt;/classXimera&gt;
%    \end{macrocode}
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