facts about web ontology languages


right now I am working on a semantic web project at my University and
therefore I need to know some facts about the following web ontology
languages RDF/S, DAML+OIL and OWL. I could not find an answer to my
questions neither in the specifications of the standards nor in any
scientific article. So I thought that maybe someone from this mailing
list can help me. I hope I have chosen the right one for those kind of

Here are my questions:
Are they completely decidable?
Is it right that only OWL full and RDF/s are not decidable, because they
do not seperate between concepts and instances?

Do DAML+OIL and OWL DL support Description logics and for this reason as
well first order predicate logic? 

And do they support first respectively second order predicate logic?
Only DAML+OIL and OWL lite and DL support first order predicate logic,
because they are based on Description logics?  

What different kinds of syntax do the above named languages support and
is it possible to map all of them to UML? 
RDF/XML, abstract syntax, n3, n-triples...I have just found several
articles, which describe methods to map RDF/S to UML. 

Is it possible to express a kind of class variable, which has one single
value for a concept? Is there a way to define one indirectly?  

Do DAML+OIL and OWL support reification and do they offer the possiblity
to add additional information to the statements? I guess that
reification has no meaning in OWL and DAML+OIL. 

Could you declare a default value for a literal, if no value was
assigned to this property?

Thanks in advance!
Best regards

Frank Clar

Received on Saturday, 11 December 2004 12:23:00 UTC