** In TeX mode, you can use the variable tex-main-file to specify the<BR>
file for tex-file to run TeX on.  (By default, tex-main-file is nil,
and tex-file runs TeX on the current visited file.)
<P>
This is useful when you are editing a document that consists of
multiple files.  In each of the included files, you can set up a local
variable list which specifies the top-level file of your document for
tex-main-file.  Then tex-file will run TeX on the whole document
instead of just the file you are editing.
<P>