I'm working with Aquamacs on a Macbook with a German keyboard. I've set the "Meta & German" option to make the alt/option key work as Alt when needed, but as Meta otherwise. So far so good. Now I want to invoke a function that is bound to C-c [ (reftex-citation). Unfortunately, I have now clue about how to type this: On the German keyboard the square bracket is bound to Alt-5, but apparently after C-c the following alt/option is interpreted by Aquamacs as Meta (or something completely different), because when I type C-c followed by Alt-5 I get the message: ^C ⌥5 is undefined. Is there a way I can get the square bracket after C-c?
（この特定のケースでは、単にreftex-citation別のキーにリバウンドしただけなので大したことではありませんが、いくつかのバリエーションで問題に遭遇したので、自分が何をしているのか、間違って理解しているのかを見つけようと思いました。）