\begin{Verbatim}[commandchars=\\\{\},codes={\catcode`\$=3\catcode`\^=7\catcode`\_=8\relax}]
\PYG{k}{\PYGZbs{}usepackage}\PYG{n+nb}{\PYGZob{}}amsthm\PYG{n+nb}{\PYGZcb{}}
\PYG{k}{\PYGZbs{}newtheorem}\PYG{n+nb}{\PYGZob{}}theorem\PYG{n+nb}{\PYGZcb{}}\PYG{n+nb}{\PYGZob{}}Stelling\PYG{n+nb}{\PYGZcb{}}
\PYG{k}{\PYGZbs{}newtheorem}\PYG{n+nb}{\PYGZob{}}lemma\PYG{n+nb}{\PYGZcb{}}[theorem]\PYG{n+nb}{\PYGZob{}}Lemma\PYG{n+nb}{\PYGZcb{}}

Uit Lemma\PYGZti{}\PYG{k}{\PYGZbs{}ref}\PYG{n+nb}{\PYGZob{}}thm:mylemma\PYG{n+nb}{\PYGZcb{}} volgt dat ...

\PYG{k}{\PYGZbs{}begin}\PYG{n+nb}{\PYGZob{}}lemma\PYG{n+nb}{\PYGZcb{}}\PYG{k}{\PYGZbs{}label}\PYG{n+nb}{\PYGZob{}}thm:mylemma\PYG{n+nb}{\PYGZcb{}}
    Lorem ipsum dolor sit
    ... eget dolor.

    \PYG{k}{\PYGZbs{}begin}\PYG{n+nb}{\PYGZob{}}proof\PYG{n+nb}{\PYGZcb{}}
        Aenean massa. Cum
        ... quis enim.
    \PYG{k}{\PYGZbs{}end}\PYG{n+nb}{\PYGZob{}}proof\PYG{n+nb}{\PYGZcb{}}
\PYG{k}{\PYGZbs{}end}\PYG{n+nb}{\PYGZob{}}lemma\PYG{n+nb}{\PYGZcb{}}
\end{Verbatim}