<math xmlns="http://www.w3.org/1998/Math/MathML" id="p1.1.m1.1" class="ltx_Math" alttext="{\displaystyle 1_{A}}" display="inline">
  <semantics id="p1.1.m1.1a">
    <msub id="p1.1.m1.1.3" xref="p1.1.m1.1.3.cmml">
      <mn id="p1.1.m1.1.1" xref="p1.1.m1.1.1.cmml">1</mn>
      <mi id="p1.1.m1.1.2.1" xref="p1.1.m1.1.2.1.cmml">A</mi>
    </msub>
    <annotation-xml encoding="MathML-Content" id="p1.1.m1.1b">
      <apply id="p1.1.m1.1.3.cmml" xref="p1.1.m1.1.3">
        <csymbol cd="ambiguous" id="p1.1.m1.1.3.1.cmml" xref="p1.1.m1.1.3">subscript</csymbol>
        <cn type="integer" id="p1.1.m1.1.1.cmml" xref="p1.1.m1.1.1">1</cn>
        <ci id="p1.1.m1.1.2.1.cmml" xref="p1.1.m1.1.2.1">𝐴</ci>
      </apply>
    </annotation-xml>
    <annotation encoding="application/x-tex" id="p1.1.m1.1c">{\displaystyle 1_{A}}</annotation>
  </semantics>
</math>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block" alttext="{\displaystyle 1_{A}}">
  <semantics>
    <mrow class="MJX-TeXAtom-ORD">
      <mstyle displaystyle="true" scriptlevel="0">
        <msub>
          <mn>1</mn>
          <mrow class="MJX-TeXAtom-ORD">
            <mi>A</mi>
          </mrow>
        </msub>
      </mstyle>
    </mrow>
    <annotation encoding="application/x-tex">{\displaystyle 1_{A}}</annotation>
  </semantics>
</math>