On Mon, Apr 30, 2012 at 2:16 PM, Alfredo Maldonado Guerra <maldo...@tcd.ie> wrote: > If you open that file in LyX 2.0.2 in Ubuntu 12.04, you get the "Undefined > control sequence" error I mentioned before. In previous versions of Ubuntu, > this doesn't happen. > The file you sent compiles just fine here, under 2.0.3 and Ubuntu 10.04. You may want to try the LyX PPA [1]. Otherwise, the error above would suggest that the \thm macro is undefined, or in more human terms it means that you are missing the package that defines it. Perhaps you are missing the 'amsthm' package? Check if you have installed all teh necessary texlive packages.
Liviu [1] https://launchpad.net/~lyx-devel/+archive/release
