<?xml version="1.0" encoding="UTF-8"?>
<math xmlns="http://www.w3.org/1998/Math/MathML">
   <mi>Φ</mi>
   <mo>=</mo>
   <msup>
      <mi>Φ</mi>
      <mfenced close=")" open="(">
         <mi>r</mi>
      </mfenced>
   </msup>
   <msup>
      <mi>Φ</mi>
      <mfenced close=")" open="(">
         <mi>s</mi>
      </mfenced>
   </msup>
</math>
