ag-gipp/GoUldI

<math 
  xmlns="http://www.w3.org/1998/Math/MathML" display="block" alttext="t element-of bold upper R Subscript plus">
  <semantics>
    <mrow data-semantic-type="infixop" data-semantic-role="unknown" data-semantic-id="5" data-semantic-children="0,4" data-semantic-content="1">
      <mi data-semantic-type="identifier" data-semantic-role="latinletter" data-semantic-font="italic" data-semantic-id="0" data-semantic-parent="5">t</mi>
      <mo data-semantic-type="operator" data-semantic-role="unknown" data-semantic-id="1" data-semantic-parent="5" data-semantic-operator="infixop,∈">∈
        <!-- ∈ -->
      </mo>
      <msub data-semantic-type="subscript" data-semantic-role="latinletter" data-semantic-id="4" data-semantic-children="2,3" data-semantic-parent="5">
        <mrow class="MJX-TeXAtom-ORD">
          <mrow class="MJX-TeXAtom-ORD">
            <mi mathvariant="bold" data-semantic-type="identifier" data-semantic-role="latinletter" data-semantic-font="bold" data-semantic-id="2" data-semantic-parent="4">R</mi>
          </mrow>
        </mrow>
        <mrow class="MJX-TeXAtom-ORD">
          <mo data-semantic-type="operator" data-semantic-role="addition" data-semantic-id="3" data-semantic-parent="4">+</mo>
        </mrow>
      </msub>
    </mrow>
    <annotation encoding="application/x-tex">t\in {\bf {R}}_{+}</annotation>
  </semantics>
</math>