Axel Missbach writes:

... unexpected acquisition behaviour ... Where is my failure? Is there another (better) way to do it? Jim Fulton gave a talk about Acquisition algebra at a conference. He explains the primary acquisition behaviour by the key sentence: "Containment before Context".

Either look at this talk on zope.org or read the acquisition section in URL:http://www.dieter.handshake.de/pyprojects/zope/book/chap3.html Dieter