Subscript & Superscript
In order to represent subscript and superscript elements, the following tags are required:
Both the <msup> and the <msub> elements may contain two elements within their tags. These two elements may, however, be two rows. If rows are used to group elements, you can have multiple elements nested within each row. For example:
<math><msup><mrow></mrow><mrow></mrow></msup></math>
All new elements added between the <row> tags will be grouped in a line. Of course you don't always have to add two rows. The <msup> and the <msub> tags will accept the following:
<math><msup><mtext>Variable</mtext><mrow><mtext>X</mtext><mtext>Y</mtext></mrow></msup></math> will output as:
So only one row element was required to add more than one superscript element.
Of course, single elements would also work for single numbers and powers etc..
<math><msup><mn>2</mn><mn>2</mn></msup></math> or