Fairly comprehensive test of many mfrac properties
<math xmlns="http://www.w3.org/1998/Math/MathML"> <mtext>Inline, styles auto, display and text </mtext> <mstyle displaystyle="false" scriptlevel="0"> <mrow> <mfrac> <mn>1</mn> <mn>2</mn> </mfrac> <mo form="infix">-</mo> <mrow> <mstyle displaystyle="true" scriptlevel="0"> <mfrac> <mn>1</mn> <mn>2</mn> </mfrac> </mstyle> </mrow> <mo form="infix">+</mo> <mrow> <mstyle displaystyle="false" scriptlevel="0"> <mfrac> <mn>1.23456</mn> <mn>7890</mn> </mfrac> </mstyle> </mrow> </mrow> </mstyle> <mtext>, the rendering should be script-size, normal-size and script-size in this example. Fraction lines should align vertically with the math axis.</mtext> </math>