Fairly comprehensive test of many mfrac properties
<math xmlns="http://www.w3.org/1998/Math/MathML"> <mtext>Inline, text style, normal line </mtext> <mstyle displaystyle="false" scriptlevel="0"> <mrow> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mrow> <mi mathcolor="gray">tan</mi> <mo rspace="verythinmathspace">⁡</mo> <mi>θ</mi> </mrow> <mn>67</mn> </mfrac> </mstyle> </mrow> </mstyle> <mtext>, numerator and denominator should render script size.</mtext> </math>