\begin{verbatim}
sub mysub {
    my @args = @_;
    return \@args;
}
\end{verbatim}
This is a default

display block

\begin{center}
Some centered text
\end{center}

Some text that is outside blocks

And now in a block.

And now no more in a block.

The footer.

things and
\begin{center}
more centered things
\end{center}

\begin{center}
more centered things
\end{center}
Text.

