Michael Schneider wrote:
Hi!
Just a few notes concerning your ideas and OWL DL (I don't know whether this
is important for you or not, but some people might find it relevant):
Thanks Michael,
Very useful and indeed relevant (thanks!).
To summarise, everything mentioned so far by me is fine in OWL Full and
RDF(s), but not in OWL DL.
Thus is it safe to say that this would be a problem in OWL DL as well?:
:x owl:sameAs 'a literal'^^xsd:string .
And I guess the take-away is, that if one was to go for something as
described in the original post, it would not be OWL DL compliant.
ps: If I get to the stage of trying to express any of this in an OWL
ontology (FULL I guess!), would it be okay to send through to cast your
eye over.
Many Regards,
Nathan
Nathan wrote:
1: Introduce a 'value' property
Where currently we can say:
:me foaf:name 'nathan' .
I'd propose introducing an ex:value property that allows us to say:
:me foaf:name [ ex:value 'nathan' ] .
or
:me foaf:name :myname .
:myname ex:value 'nathan' .
The FOAF spec defines foaf:name as a owl:DatatypeProperty [1], and therefore
cannot be used in OWL DL with blank nodes (representing anonymous
individuals) or URIs (representing named individuals) in object position. No
problem with RDF(S) or OWL Full, though.
I'm hoping the basic human understanding of this is pretty obvious,
sorting out the domain & range of ex:value, class of :myname, ontology
details and related are hurting my head a bit at the minute.
And thus you could describe a value:
:me foaf:name [
ex:value 'nathan' ;
ex:type xsd:string ;
In OWL DL, you cannot use a datatype name in the object position of an
object or data property (ex:type will be either an object property or a data
property). If this was a typo and you really mean "rdf:type", it is still
not allowed in OWL DL, since xsd:string is not a class in OWL DL. Again, it
is fine in RDF(S) or OWL Full.
And do some funkier stuff:
:me foaf:mbox :myemail ;
:myemail ex:value <mailto:[email protected]> ;
Above, you use ex:value with literals, but here you use it with a URI. In
OWL DL, you have to decide for one: either ex:value is a data property, then
URIs are not allowed; or it is an object property, then literals are not
allowed. Again, no problems with RDF(S) and OWL Full.
Michael
[1] http://xmlns.com/foaf/spec/20100101.rdf
--
Dipl.-Inform. Michael Schneider
Research Scientist, Information Process Engineering (IPE)
Tel : +49-721-9654-726
Fax : +49-721-9654-727
Email: [email protected]
WWW : http://www.fzi.de/michael.schneider
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