Test dot accent and accentunder=false on mstyle, munder, mo.
<math xmlns="http://www.w3.org/1998/Math/MathML"> <mstyle mathsize="200%" displaystyle="false"> <munder> <mi>x</mi> <mo> ˙</mo> </munder> <mo> ≠</mo> <mstyle accentunder="false"> <munder> <mi>x</mi> <mo> ˙</mo> </munder> </mstyle> <mo> =</mo> <munder accentunder="false"> <mi>x</mi> <mo> ˙</mo> </munder> <mo> =</mo> <munder> <mi>x</mi> <mo accent="false"> ˙</mo> </munder> </mstyle> </math>