<mtext>

The <mtext> MathML element is used to render arbitrary text with no notational meaning, such as comments or annotations.

To display text with notational meaning, use <mi>, <mn>, <mo> or <ms> instead.

<math display="block">
  <mtext>Theorem of Pythagoras</mtext>
</math>

<math display="block">
  <mtext>/* comment here */</mtext>
</math>