/usr/share/lyx/layouts/extarticle.layout is in lyx-common 2.0.6-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 | #% Do not delete the line below; configure depends on this
# \DeclareLaTeXClass[extarticle]{article (more font sizes)}
# Herbert Voss <voss@lyx.org>
Format 35
Input article.layout
# change available fontsizes
ClassOptions
FontSize 8|9|10|11|12|14|17|20
end
|