Re: Handling multiple rdfs:ranges

On Tue, Feb 23, 2016, at 17:05, Peter F. Patel-Schneider wrote:
> On 02/23/2016 07:31 AM, Reto Gmür wrote:
> >[...]
> > 
> > Granted, the semantics of :rangeIncludes are very weak (under OWA) but
> > the fact that you can create contradictions with it shows that it's not
> > completely meaningless.
> > 
> > ex:prop1 s:rangeIncludes :Cat .
> > :Cat owl:disjointWith :Dog .
> > ex:prop1 owl:range :Dog .
> > 
> > The above graph evaluates to false in every possible world, this is not
> > the case if you omit any of the 3 triples, this shows that
> > `s:rangeIncludes` is not a meaningless decoration.
> > 
> > Reto
> 
> I don't think that this follows from the semantics of :rangeIncludes,
> even if
> you augment schema.org semantics with disjointness.

In the example I also used "owl:range" to create what I thought is a
contradiction.
> 
> Perhaps one could also count the documentation of
> rangeIncludes as authoritative as well.  So from
> https://schema.org/rangeIncludes, rangeIncludes "[r]elates a property to
> a
> class that constitutes (one of) the expected type(s) for values of the
> property" would also be part of the semantics of schema.org ranges.

I considered only this definition. And based on that I still think there
is a contradiction, if the owl:range of a property excludes :Cat (which
is expressed with the statements using owl-properties), :Cat cannot at
the same time "be (one of) the expected type(s) for values of the
property".

Reto

Received on Tuesday, 23 February 2016 16:25:21 UTC