Fairly comprehensive test of many mfrac properties
<math xmlns="http://www.w3.org/1998/Math/MathML"> <mtext>Inline, display style, normal line </mtext> <mstyle displaystyle="false" scriptlevel="0"> <mrow> <mstyle displaystyle="true" scriptlevel="0"> <mfrac> <mrow> <mi mathcolor="gray">ln</mi> <mo rspace="verythinmathspace">⁡</mo> <mi>x</mi> </mrow> <mi>y</mi> </mfrac> </mstyle> </mrow> </mstyle> <mtext>, numerator and denominator should render normal size.</mtext> </math>