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
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