<FRAGMENT parents="section p">
    <quantity>
        <mag>2\pi</mag>
        <unit base="radian"/>
    </quantity>
    <quantity>
        <mag>21\pi45\pi234\pi890</mag>
        <unit base="radian"/>
    </quantity>.
    <quantity><mag>9192631770</mag></quantity>
    <quantity>
        <mag>2<m>\pi</m></mag>
        <unit base="radian"/>
    </quantity>
</FRAGMENT>