On Tue, May 10, 2016 at 3:28 PM drymer <drymer@autistici.org> wrote:
I evaluated the
functions, and supposedly it should something like \ast when executing
C-u *, but it doesn't happen.

I reread your initial email.. so look like you see nothing getting inserted when in do "C-u *"? That is odd.

Can you do the following and see if things work as intended? If they do, then there's something conflicting with your config:

1. Launch emacs -Q

2. Paste the whole code block from http://emacs.stackexchange.com/a/16746/115 to the *scratch* buffer and evaluate it.

3. Do C-x b something.org

4. M-x org-mode

5. Hit "C-u *"

6. You should see an asterisk being displayed, which is actually a prettified version of "\ast{}" which is what actually got inserted.

Also, please report your emacs and org-mode versions. I am using the latest build of emacs-25 branch from git and the latest build of org-mode master branch git.