iv>
  <!-- <msub>, <msup>, <msubsup>, <munder>, <mover>, <munderover>,
       <mmultiscripts>, <mfrac> are embellished
       operators if their first in-flow
       child exists and is an embellished operator -->
  <p>
    <math>
      <mn>X</mn>
      <msub class="testedElement">
        <mo lspace="2em" rspace="0em">X</mo>
        <mn>X</mn>
      </msub>
      <mn>X</mn>
    </math>
  </p>
  <p>
    <math>
      <mn>X</mn>
      <msup class="testedElement">
        <mo lspace="2em" rspace="0em">X</mo>
 