[topicmapmail] Opera topic map question

[Alexander Mikhailian]

Thanks for the hint, these are excellent topic maps. 

> Feedback on any- and everything to
> do with modeling issues, content, etc. is very welcome.

Actually, I browsed already through the Italian Opera topic map and here
is one question.

* Writers, composers and librettists do not depend on persons. However,
in the context of this precise topic map, I would find it useful to see
a supertype-subtype hierarchy under "person".

* Dates do not form a hierarchy either, although I would naturally
expect "date-of-birth" be the subtype of "date" also. 

In my opinion, the only reason for not creating a hierarchy for these
two topic sets is because  these topics are referenced by PSIs and a
hierarchy would contain assumptions about the relations between topics
referred by PSIs that are not true outside this precise topic map.

Since the Italian Opera topic map is an exemplary document, I believe
it's ontology has been thoroughly thought and the possible hierarchies
are not there for a reason ;-)

-- 
Alexander Mikhailian