I don't think Emacs has a mapping from the decomposed form back to the original character. You can look it up using ucs-names though:
(defun lookup-composed (decomp)
(maphash (lambda (key val) (when (equal
(get-char-code-property val 'decomposition))
I'm not sure about the feasibility of this.
First, I believe this requires a backwards font on the system. I'm no expert on how text is actually rendered but, speaking generally, text is rendered using a "base description", such as a vector mapping. This base information is contained in a font file, such as a .ttf. Without some mapping, Emacs doesn't ...
I'm no expert on this, and this might not be the right way to do it, but I think this will do it for you:
(define-key global-map (kbd "M-'") iso-transl-ctl-x-8-map)))
iso-transl-ctl-x-8-map is a variable whose value is the keymap I think you're looking for, to bind to M-'. iso-transl-ctl-x-8-map is the value returned by this: