Gmail Multiple Inboxes

Hi all,
Just spent the last 2 hours trying to find out how Gmails query syntax works. And I hope this post will help others not to loose 2 hours too.
 
This weekend I discovered a nice Gmail Lab "thingy" multiple inboxes. A nice little feature which helps you better organize your inbox, especially if you have a large monitor.
I tried setting it up to help for my TODO tasks management. So I created 2 new labels: @TODO and @Done (I hope their meaning is obvious). All went fine untill I wanted to have a view with the TODOs I still have to do, simply "has label @TODO but not @Done".
The solution required as mentioned above about two hours. And came after reading: http://mail.google.com/support/bin/answer.py?hl=en&answer=7190 and is "-Label:@Done Label:@TODO".
 
I hope this will be helpful for somebody as the query language is for the Gmail search also.
 
See you soon, as I recently went on a trip at an abandon "castle" and took some pretty pictures.
 
Have fun.
Dan