Emacs is famous for causing tendinitis, but one must remember that Ctrl and Alt come in pairs, at left and right of the keyboard :-)
However, in Ubuntu 16.04, Alt R behavior is Alt Gr, messing with Emacs shortcuts. Thus usually I type Esc+X instead of Alt+X for the sake of my fist.
Thus, how could we:
~/.emacs.d/init.elto understand Alt Gr as Alt R (or)
- Change the Alt Gr behavior for all applications
It is not about creating a shortcut, its about change the key mapping.