<?xml version="1.0" encoding="UTF-8"?>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">  <munderover>    <mrow>      <munderover>        <mi mathvariant="normal">BASE</mi>         <mi mathvariant="normal">under-1</mi>         <mi mathvariant="normal">over-2</mi>       </munderover>     </mrow>     <mi mathvariant="normal">under-2</mi>     <mi mathvariant="normal">over-1</mi>   </munderover>   <mo>=</mo>   <munderover>    <mrow>      <munder>        <mrow>          <mover>            <mi mathvariant="normal">BASE</mi>             <mi mathvariant="normal">over-2</mi>           </mover>         </mrow>         <mi mathvariant="normal">under-1</mi>       </munder>     </mrow>     <mi mathvariant="normal">under-2</mi>     <mi mathvariant="normal">over-1</mi>   </munderover> </math>