Am 20.05.2011 16:44, schrieb John R Hudson:
You can download cancel.sty from here http://ctan.binkerton.com/ctan.readme.php?filename=macros/latex/contrib/misc/cancel.sty
It is not recommended to install packages manually if you are new in LyX because this requires some extra knowledge. Therefore please try out what I suggested in my previous mail.
You will need to run Tools>Reconfigure in 1.6.x to ensure that LyX finds it (I assume it is the same in LyX 2.0).
This is not necessary in this case. (This is only necessary if you install new layout and LaTeX class files.) (But it also don't hurt.)
regards Uwe
