"<math class="mwe-math-element mwe-math-element-inline" xmlns="http://www.w3.org/1998/Math/MathML"><mrow data-mjx-texclass="ORD"><mstyle displaystyle="true" scriptlevel="0"><mrow data-mjx-texclass="ORD"><mtable columnalign="right left right left right left right left right left right left" columnspacing="0em 2em 0em 2em 0em 2em 0em 2em 0em 2em 0em" displaystyle="true" rowspacing="3pt"><mtr><mtd><mi>F</mi><mo stretchy="false">(</mo><msub><mi data-mjx-texclass="OP" mathvariant="normal">id</mi><mrow data-mjx-texclass="ORD"><mi>X</mi></mrow></msub><mo stretchy="false">)</mo></mtd><mtd><mo stretchy="false">=</mo><msub><mi data-mjx-texclass="OP" mathvariant="normal">id</mi><mrow data-mjx-texclass="ORD"><mrow data-mjx-texclass="ORD"><mi>F</mi><mo stretchy="false">(</mo><mi>X</mi><mo stretchy="false">)</mo></mrow></mrow></msub></mtd></mtr><mtr><mtd><mi>F</mi><mo stretchy="false">(</mo><mi>f</mi><mo stretchy="false">∘</mo><mi>g</mi><mo stretchy="false">)</mo></mtd><mtd><mo stretchy="false">=</mo><mi>F</mi><mi>f</mi><mo stretchy="false">∘</mo><mi>F</mi><mi>g</mi></mtd></mtr></mtable></mrow></mstyle></mrow></math>"^^http://www.w3.org/1998/Math/MathML