<!DOCTYPE html> <html> <head> <title>mphantom</title> <meta charset="utf-8"/> </head> <body> <!-- Test different kinds of content inside <mphantom>. --> <p><math> <mrow style="visibility: hidden"> <msqrt> <mfrac> <mn>1</mn> <mi>x</mi> </mfrac> </msqrt> <mo>+</mo> <menclose notation="box updiagonalstrike"> <mover> <mspace width="3em" height="1em" mathbackground="red"/> <mo>‾</mo> </mover> </menclose> </mrow> </math></p> </body> </html>