<html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Check width of stretchy OverBar</title> <style type="text/css"> html { background-color: grey; } div { display: inline-block; font-size: 30px; line-height: 60px; /* Ensure space for underbar */ border: 1px solid white; padding: 2px; /* 10% error allowed in char selection */ background-color: black; color: black; } </style> </head> <body> <div> <math xmlns="http://www.w3.org/1998/Math/MathML"> <munder> <mn>1</mn> <mo>̲</mo> </munder> </math> </div> </body> </html>