<FRAGMENT parents="theorem proof">
    <case>
        <title>Special Case</title>
        <p>This case</p>
    </case>
    <case direction="forward">
        <p>This case</p>
    </case>
    <case direction="backward">
        <p>This case</p>
    </case>
    <case direction="forward">
        <title>Special Case</title>
        <p>This case</p>
    </case>
</FRAGMENT>