Fairly comprehensive test of many mfrac properties
<math xmlns="http://www.w3.org/1998/Math/MathML"> <mtext>Inline, display style, thick line </mtext> <mstyle displaystyle="false" scriptlevel="0"> <mrow> <mstyle displaystyle="true" scriptlevel="0"> <mfrac linethickness="1pt"> <mrow> <mi>x</mi> <mo form="infix">-</mo> <mn>1</mn> </mrow> <mrow> <mrow> <mn>0.98</mn> <mo form="infix">×</mo> <msup> <mn>10</mn> <mn>2</mn> </msup> </mrow> <mo form="infix">+</mo> <mi>y</mi> </mrow> </mfrac> </mstyle> </mrow> </mstyle> <mtext>, the superscripted 2 should be script size.</mtext> </math>