How to use Quail Completion

[Rasmus <rasmus@gmx.us>]

In message-mode I use input method TeX (see C-h I TeX).  I use:

(add-hook 'message-mode-hook
	  (lambda ()
	    (set-input-method "TeX")))

Strings like \"A has several completions. From the *Help* string:

    key	 character(s)  [type a key (sequence) and select one from the list]
    -------- ------------
    \"A	 Ӓ Ǟ Ä

When I type \"A and TAB I get the list "Ӓ Ǟ Ä", but I can't figure out
how to get from "Ӓ" to "Ä".  I have tried with C-u-TAB, C-TAB, M-TAB
etc.  I have tried to use the mouse to select an alternative completion,
but that doesn't work either.  I have tried without vanilla Emacs (emacs
-q).

So to summarize, how do I use "select one from the list"?  Or, how to
get from Ӓ to Ä?

Thanks,
Rasmus

-- 
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