Scott, this is a very helpful explanation. I have to think of this as having the same scope as the inference engine. If the interference engine has visibility to this at interference time, it will infer the additional triples. I must refrain from saying it 'redefines' because as the book says: it 'extends' - as in it extends the owl inferencing.
The book's example has a functional objective to 'streamline' the declaration of an 'inverseOf' that is two-way; that is exactly what it does. Thanks for helping me with this understanding. Regards, --tk On Wed, Dec 10, 2008 at 10:53 AM, Scott Henninger < [EMAIL PROTECTED]> wrote: > > Oops, you're right. So is the book. It's a type def stating that the > inverseOf property is a type of property (symmetric). Sorry to > confuse things. > > It's still the case, though, that owl:inverseOf is not being > redefined. We've added a definition to owl:inverseOf that will create > a new triple each time it is used. I.e. if you have a triple: > xyz owl:inverseOf abc > then 'owl:inverseOf rdf:type owl:SymmetricProperty' will add the > triple > abc owl:inverseOf xyz > > ...as it would for any triple that uses owl:inverseOf. the definition > of owl:inverseOf does not change. > > As this is a forum for TopBraid Composer discussion and not general > Semantic Web issues, I'd suggest taking a look at > http://www.workingontologist.org/ > or contactign the authors. > > -- Scott > > On Dec 10, 11:36 am, "tk blast" <[EMAIL PROTECTED]> wrote: > > Scott, this is very helpful and I can see how SPARQL CONTRUCT would be > > useful as yet another method of triple creation. > > > > If there is a problem with my triple then there is an errata in the > Allemang > > & Hendler book because the triple is taken directly from the solution on > > page 131. I'll quote it here so that it may be useful to others: > > > > > --------------quoted from book begin----------------- > > > Since we want owl:inverseOf to work in both directions, this can be > done > > > easily by asserting that owl:inverseOf is its own inverse, thus: > > > owl:inverseOf owl:inverseOf owl:inverseOf . > > > > > You might have done a double take when you read that owl:inverseOf is > its > > > own inverse. Fortunately, we have a more readable and somewhat more > > > understandable way to say this - namely: > > > owl:inverseOf rdf:type owl:SymmetricProperty . > > > --------------quoted from book end----------------- > > > > What I am trying to figure out is prior to this declaration, > owl:inverseOf > > only works one-way, after this is defined, owl:inverseOf will work in > both > > directions. > > > > If I were to fererate across two respostiries where one of them redefined > > the owl:inverseOf in this manner, it would be change at a global level. > > > > --tk > > > > On Wed, Dec 10, 2008 at 8:15 AM, Scott Henninger < > [EMAIL PROTECTED] > > > > > > > > > wrote: > > > > > Hello; There is a problem with your triple in that owl:inverseOf is a > > > property and is used as the subject in "owl:inverseOf rdf:type > > > owl:SymmetricProperty". That's not allowed, so the redefinition > > > couldn't happen. > > > > > In addition, redefining rdf/rdfs/owl terms will not happen via > > > inference. You can extend these - for example creating a subproperty > > > of rdfs:label. And this is the intent of the Allemang & Hendler pages > > > you cite. > > > > > In general, though, inferencing can be aggressive and the ontology has > > > to be designed with care. This is one of the reasons TopQuadrant is > > > spending resources to use SPARQL CONSTRUCT, for example, to provide > > > infrastructure for more controlled "inferencing". Take a look at > > >http://spinrdf.org, which is part of these overall efforts. > > > > > -- Scott > > > > > On Dec 9, 6:15 pm, "tk blast" <[EMAIL PROTECTED]> wrote: > > > > Hello fellow, > > > > in the Allemang/Hendler book, on page 130-131 there is a discussion > about > > > > OWL to Extend OWL. > > > > I want to make sure I understand the ramification of this type of > > > assertion. > > > > > > If I were to import a file.owl that contained the triple: > > > > owl:inverseOf rdf:type owl:SymmetricProperty . > > > > it would redefine owl:inverseOf for all instances right? > > > > > > I guess what i am asking is when one goes about redefining items in > the > > > owl > > > > namespace, > > > > appropriate care must be given to the scope of those assertions. > Just > > > like > > > > rdfs:domain and rdfs:range, the inferences are aggresive and must be > > > treated > > > > with care. > > > > > > --tk > > > > > > -- > > > > > > "The nervous system organizes itself so as to compute a stable > reality" - > > > > Maturana & Varela > > > > -- > > > > "The nervous system organizes itself so as to compute a stable reality" - > > Maturana & Varela > > > -- "The nervous system organizes itself so as to compute a stable reality" - Maturana & Varela --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "TopBraid Composer Users" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/topbraid-composer-users?hl=en -~----------~----~----~----~------~----~------~--~---
