Re: Handling multiple rdfs:ranges

Hi Fabian, Reto and Graham,

That is good news that most ontologies use owl:UnionOf and somewhere
Bioportal does the same. It may be somewhere else in the stack that is
causing queries such as the following:

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX bpo: <http://www.semanticweb.org/ontologies/2010/10/BPO.owl#>

SELECT ?x
WHERE {
bpo:has_event rdfs:domain ?x .
}

to return multiple types, where it should return one owl:unionOf
collection, as Graham describes.

Reto's suggestion of using schema:rangeIncludes matches the *some*
semantics, informally at least. Do you know whether there is an established
model theory for the semantics of this predicate; and, perhaps more
importantly, whether there is significant adoption?

Regarding monotonicity, if we take AZ's nice example again. Assume that we
design a dataset using ex:myProperty rdfs:domain ex:Person, containing
Graham (for comic effect only, no offence) as the subject of a triple with
property ex:myProperty. In an open world, someone can come along and extend
the ontology with ex:myProperty rdfs:domain ex:Woman; and now.. Graham is
inferred to be a woman. The hypothetical weaker semantic for multiple
domain/range wouldn't make the same mistake.

Is this the kind of monotonicity problem you mean, or was there a different
monotonicity problem in fact in favour of the stronger semantics?

Best regards,

Ross



On 23 February 2016 at 18:49, Fabian Cretton <Fabian.Cretton@hevs.ch> wrote:

> As Graham explains, I think many ontologies now use the owl:unionOf
> construct to handle mutliple ranges.
> And so do tools as Protégé.
>
> See for instance the schema.org ontology[1] where mutliple domain/range
> are often used.
> Here is an example:
> schema:about a rdf:Property;
>     rdfs:label "About"@en;
>     rdfs:comment "The subject matter of the content."@en;
>     rdfs:domain [ a owl:Class; owl:unionOf (schema:CommunicateAction
> schema:CreativeWork) ];
>     rdfs:range schema:Thing;
>
> The Bioportal  ontology certainly does so as well.
>
> Fabian
>
>
>
> [1] http://schema.rdfs.org/
> >>> Graham Klyne <gk@ninebynine.org> 23.02.2016 11:35 >>>
>
> On 23/02/2016 09:24, Ross Horne wrote:
> > My follow up question is: whether anyone knows whether the more
> > accommodating inference, as implied by Bioportal, was ever discussed
> during
> > the RDFS standardisation process; and if so, why the more restrictive
> > definition for multiple domains and ranges was chosen.
> >
> > I suspect this question has a simple explanation in model theory, which
> is
> > why I also copy Pat.
> >
>
> I recall this was discussed in the 2000-2004 RDF working group, or at
> least
> among some members of the working group at that time.
>
> A concern here is for logical monotonicity - the introduction of new
> knowledge
> cannot invalidate existing knowledge, otherwise how can one know for sure
> that
> anything you think you know is actually true in a context that invokes
> open-world semantics?
>
> There are alternative models (e.g. default reasoning), but in order to
> draw firm
> confusions they require assuming that one has a complete set of assertions
> (i.e.
> no more can be added).
>
> Also from the 2000-2004 RDF working group (which ran in parallel with the
> first
> OWL working group), the RDF list construct (aka
> rdf:parseType="Collection") was
> introduced so that (among other things) OWL could make closed assertions,
> such
> as owl:unionOf (see
> https://www.w3.org/TR/2004/REC-owl-guide-20040210/#SetOperators).
>
> #g
> --
>
>
>