<?xml version="1.0" encoding="UTF-8"?>
<math xmlns="http://www.w3.org/1998/Math/MathML">
   <mfenced close=")" open="(">
      <msub>
         <mi>η</mi>
         <mrow>
            <mi>μ</mi>
            <mi>ν</mi>
         </mrow>
      </msub>
   </mfenced>
   <mo>=</mo>
   <mrow>
      <mi>d</mi>
      <mi>i</mi>
      <mi>a</mi>
      <mi>g</mi>
   </mrow>
   <mfenced close=")" open="(">
      <mn>-1</mn>
      <mn>1</mn>
      <mn>1</mn>
      <mn>1</mn>
   </mfenced>
</math>
