Hello, > > (/usr/share/texmf/omega/lambda/base/lambda.tex > > ! Undefined control sequence. > > This might be http://bugs.debian.org/49955 That's what I thought too. But this seems to be deeper into the lambda.tex file. Earlier the ungetc error happened right at the beginning. Could we have a look at the log file lambda.log which would have been produced by omega? Regards, Kapil.