Re: Anyone working on an extension to SWRL to handle RDF*?

Dear Finn,

I was very interested in reading about your idea about having rules on 
top of RDF*. I work in the N3 community group where we aim to propose a 
standard for N3, another rule-language for the semantics web. N3 already 
supports citation of graphs (not triples as RDF*).

In N3 you can express triples including graphs

     {:man :hasSpouse :woman} :startDate "1970-01-01"^^xsd:date .

and you can write rules on top of your triples like for example:


     { {?P1 :hasSpouse ?P2} :startDate ?D } *=>* { {?P2 :hasSpouse ?P1} 
:startDate ?D}.

This rule applied to the previous triple would actually result in

     {:woman :hasSpouse :man} :startDate "1970-01-01"^^xsd:date .


We would like to align with RDF* but it will also depend on RDF*'s 
semantics whether we can assume that cited N3 graphs containing one 
single triple are actually the same as RDF* expressions, i.e. whether

{:man :hasSpouse :woman} :startDate "1970-01-01"^^xsd:date . and <<:man 
:hasSpouse :woman>> :startDate "1970-01-01"^^xsd:date .

have the same meaning. If that will be the case, the derivation you 
propose is already supported by N3. Otherwise, we need to see how these 
constructs relate.

If you want to play with N3, you can try our online tutorial of N3: 
https://n3.restdesc.org/
In the tutorial there are different reasoning windows which actually 
call the EYE reasoner (http://eulersharp.sourceforge.net/) in the 
background. So, if you want a first try, you can add your facts and 
rules and press "Execute EYE". If you would like to include OWL-RL, you 
can find the rules here: 
http://eulersharp.sourceforge.net/2003/03swap/eye-owl2.html

Of course that is not RDF* yet, but when the semantics is fixed we plan 
to improve here.

Kind regards,
Doerthe


Am 01.06.20 um 04:36 schrieb Tim Finin:
> I'm late to the game and just started experimenting with RDF* using 
> Stardog's implementation. It didn't take me long to realize that I was 
> not in Kansas anymore. :-)
>
> I started with a simple example:
>
>     <<:man :hasSpouse :woman>> :startDate "1970-01-01"^^xsd:date .
>
>
> and thought to add
>
>
>     :hasSpouse a owl:SymmetricProperty .
>
> Stardog did the right thing and added a triple <<:woman :hasSpouse 
> :man>>, so I was happy.
>
> But then wanted to add a general way to represent the constraint that
>
>     <<?P1 :hasSpouse ?P2>> :startDate ?D *=>*  <<?P2 :hasSpouse ?P1>>
>     :startDate ?D
>
>
> This seemed very reasonable, at least for the normal semantics for the 
> human spouse relation.
>
> I don't think there is a way to enforce this in OWL DL and assume that 
> there's no version of SWRL that can handle RDF*.  I'm unsure if a SWRL 
> rule using the reification model will work and even if it does, it 
> seems to defeat the purpose of RDF*.
>
> I could do that with a SPARQL query, but that doesn't seem right -- 
> I'd like to make this constraint be part of the schema/ontology.
>
> Is anyone aware of work on a SWRL reasoner that can work with RRF*?
>
> Tim
>
> --
> Tim Finin,  Willard and Lillian Hackerman Chair in Engineering,  
> Computer Science and
> Electrical Engineering, U. Maryland, Baltimore County, 1000 Hilltop 
> Circle, Baltimore MD
> 21250. http://umbc.edu/~finin, finin@umbc.edu 
> <mailto:finin@umbc.edu>,tfinin@gmail.com <mailto:tfinin@gmail.com>, 
> mobile:410-499-3522

-- 
Dörthe Arndt
Researcher Semantic Web
imec - Ghent University - IDLab | Faculty of Engineering and Architecture | Department of Electronics and Information Systems
Technologiepark-Zwijnaarde 122, 9052 Ghent, Belgium
t: +32 9 331 49 59 | e: doerthe.arndt@ugent.be