When I am writing slides, I usually use one master file and several dependent files; as a macro package I use beamer. I would like to access the environments defined by the beamer package also in the dependent files (which I include through \input) through C-c C-e. I can access them in the master file. By the same token, I would like to access the macros in my macro packages, which I also include through \input. My .emacs file contains the lines
(setq-default TeX-master nil)
(setq TeX-parse-self t)
(setq TeX-auto-save t)
Any suggestions?

LaTeX-default-styletobeamerhelp, e.g. putting (setq LaTeX-default-style beamer)` in your emacs or by putting-*- mode: LaTeX; LaTeX-default-style: beamer; -*-in the first line of the dependent files? – N.N. Dec 12 '12 at 9:51