# Firefox 4 and MathJax \not

I'm currently using Firefox 4.0 on OS X, with STIX fonts installed, and for some reason MathJax (in HTML-CSS mode) is not rendering the \not symbol at all, i.e. for me $a \not = b$ looks like $a = b$ rather than $a \ne b$. This rendering problem seems to be limited to StackExchange; I don't have any problems on MathOverflow. Chrome and Safari also render \not correctly.

• I experience similar problems with FF 4.08 (I think) that I installed in my office computer (on windows XP), all the TeX fonts look extra-crummy. I do recall, however, that there's no official support to beta browsers... so I'm still waiting until FF 4 comes out officially before I complain :-) – Asaf Karagila Jan 16 '11 at 14:38
• On Firefox 4, to get decent math display, I have to right-click on a piece of math, go to Settings->Math Renderer and pick "MathML". With "HTML/CSS" the output is very bad. That being said, there is certainly some problem with the "not" symbol. It isn't placed correctly, and if I switch rendering modes from MathML to HTML and back, it doesn't end up in the same place it was. It ends up on the far left end of the = sign. – Carl Mummert Mar 22 '11 at 13:34
• I have sometimes seen the problem even on Firefox 3, FWIW. – ShreevatsaR Apr 2 '11 at 7:03