&lt;!DOCTYPE informalexample PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
          "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"&gt;
&lt;informalexample&gt;
&lt;programlisting&gt;
sub print_content_model {
    my($self) = shift;
    local($_) = shift;
    local(*FILE) = shift;

    my(@cm) = $self-&gt;format_content_model2($_);
    foreach $_ (@cm) {
        print FILE $self-&gt;make_links($_, 1, 1), "\n";
    }
}
&lt;/programlisting&gt;
&lt;/informalexample&gt;