[Mediawiki-l] Categories as filter

["Thomas U. Grüttmüller"]

Huhu :-)

If I want to find pages that are listed in both category A and category 
B, is there an easy way to do so?

Example 1: find on Wikipedia composers who are dead for more than 70 years

Example 2: find on Commons videos or animations that are in the Public 
Domain

Thanks in advance,
   Thomas