Marcus Beyer wrote: > On LyX I did Edit->Reconfigure. Then I restarted > LyX, but I see no effect on math formulas. > > Is there a special trick to do?
You have to tell LyX that you want these previews. There's a check button on the Edit->Preferences dialog. Find it: (xforms) Look 'n' Feel->Misc tab (qt) Look and Feel->Graphics -- Angus