$child = xml_child(parent => $elt, child => 'built', action => 'after', relto => $prev_child, def_text => '19700101 000000.000-0000');
$prev_child = $child; $child = xml_child(parent => $elt, child => 'shareable', action => 'after', relto => $prev_child, override_text => 'true');