/merror></math>
    <math><mphantom><mspace style="visibility: visible;" id="abovePhantom" width="10px" height="30px" style="background: purple"></mspace><mspace style="visibility: visible;" id="belowPhantom" width="10px" depth="30px" style="background: blue"></mspace></mphantom></math>
    <math><mspace id="aboveMath" width="10px" height="30px" style="background: purple"></mspace><mspace id="belowMath" width="10px" depth="30px" style="background: blue"></mspace></math>
    <!-- menclose is treated as <unkn