On German keyboards many important Emacs commands are not easily
accessible.  In particular C-/ (undo) and M-/ (dabbrev-expand)
are very difficult to type (i.e. one types C-Shift-7 or M-Shift-7) thus
hampering the smooth flow of typing, Emacs users with US-american keyboards
enjoy.

Redefining the keys that are present on the same position does not seem
to be a good idea since this would undermine the canonical meaning of
certain keys.  In particular at the place of / there is -  on German
keyboards.

Fortunately the German keyboard offers the ä (a umlaut) key which has no
predefined binding yet.  Since ä is located at a quite comfortable place
(at the place of ') C-ä and M-ä come quite smoothly similar to C-/ and M-/.
Also C-ä and M-ä are very mnemonic representing the two äh's of German:
The correcting one and the mmh-ähh :-)

How can I correctly define M-ä in the most canonical way?

By more or less trial and error I found the following working under 21.3,
and an older 21.2.50 (of April 2002).  It does no more work under the
current 21.3.50 which is not surprising anyway.

To me this seems to be some kind of boot strap problem: In order to
mention ä one needs to be in a Latin-1 language environment etc.  But the
point would be that this key definiton is even present in other environments.

(global-set-key [(control ?\344)] 'undo)
(global-set-key [(meta ?\344)] 'dabbrev-expand)
(global-set-key [(meta shift ?\344)] 'dabbrev-last-expansion)

-- 
Ulrich Neumerkel http://www.complang.tuwien.ac.at/ulrich/