RE: RDF and OWL rules

> -----Original Message-----
> From: www-rdf-rules-request@w3.org
[mailto:www-rdf-rules-request@w3.org]
> On Behalf Of Jos De_Roo
> Sent: Tuesday, April 01, 2003 3:24 PM
> To: geoff@sover.net
> Cc: 'RDF Rules'
> Subject: RE: RDF and OWL rules
> 
> 
> 
[...]
> 
> > I seem to have mostly a subset of your rules - i.e. the rules I have
> > (with the exception of a couple) correspond to rules that you have.
I
> > don't have a number that you have:
> >
> > rule3r2
> > rule5e2, rule5e2
> 
> guess you meant e1?

e3, I think.
 
[...]
> >
> > Rules that you don't seem to have (but may have been derivable by
other
> > means?):
> >
> > someValuesFrom, owl:equivalentClass, owl:complementOf
> 
> right for owl:someValuesFrom
> for owl:equivalentClass we have
>   owl:equivalentClass rdfs:subPropertyOf rdfs:subClassOf;
>                       a owl:SymmetricProperty;
>                       a owl:TransitiveProperty.
>   {:rule7c1. ?a rdfs:subClassOf ?b. ?b rdfs:subClassOf ?a}
>                       => {?a owl:equivalentClass ?b}.

Right. I'd missed the consequence of:
 	
	:equivalentClass rdfs:subPropertyOf rdfs:subClassOf

and so had added an unnecessary explicit rule:

	infer {[rdf:type] ?a ?c} from {[rdf:type] ?a ?b} 
		and {[owl:equivalentClass] ?b ?c};
 
> for owl:complementOf we are still trying negation (by declaration)
>   owl:complementOf a owl:SymmetricProperty.
>   {:rule60n1. ?A owl:complementOf ?B. ?C a ?A} => {?C neg:type ?B}.
>   {:rule60n2. ?A owl:oneOf ?L. ?L neg:item ?C} => {?C neg:type ?A}.
>   {:rule60n3. ?A owl:complementOf ?B. ?C neg:type ?A} => {?C a ?B}.

I had a weak rule for this:

	infer {[owl:differentFrom] ?x ?y} from {[rdf:type] ?y ?c2} 
		and {[owl:complementOf] ?c1 ?c2} and {[rdf:type] ?x
?c1};

That would go away if owl:complementOf is considered subPropertyOf of
owl:disjointWith. I don't think it is though. Could be another path I
missed...

> 
> > A few notes:
> >
> > - seems like either rule4p1 or rule4p2 is necessary, but not both
> > (assuming equivalentProperty is stated as symmetric)
> 
> right, good catch; corrected
> 
> > - rule8s6 seems unnecessary (derivable by other rules)
> 
> Well, if I leave it out we get 5 more tescases with
> "no proof found" (but we test with --step 100000)
> I believe that some redundacy is not bad in practice?

Sure, performance is a good thing also :-)

We might want to consider somehow noting the more complex rules that
exist for performance reasons alone (if any?) when they can be derived
from the more basic axioms.

> 
> > - what are the semantics of math:proofCount? Are your cardinality
> > inconsistency rules making a unique names assumption?
> 
> math:proofcount is an experimental builtin
> to count how many different proofs can be
> found for the subject graph posed as query
> against the loaded kb (just to experiment)
> (will check no-una again but I thought that
> http://www.w3.org/2002/03owlt/maxcardinality/inconsistent001
> http://www.w3.org/2002/03owlt/maxcardinality/inconsistent002
> were done OK as they needed explicit owl:differentIndividualFrom
> (now called owl:differentFrom) statements)

But if the owl:differentFroms weren't supplied, then it would wrong to
claim a cardinality violation (instead you'd have to infer that at least
one of the things is the sameAs another.)
 
> 
> > - Seems that most inconsistencies (with exception of datatype
violations
> > and some cardinality issues) stem from something being both the
sameAs
> > and differentFrom something else or a class being both a subClassOf
and
> > disjointWith/complementOf another class. How does neg:type fit in?
> 
> we have to work that out...
> good idea to think about that one
> 
> > Looks promising - the commonality of results created from separate
> > efforts is a good sign. I'm going to bring my rules up to speed with
> > yours before publishing them. Then I'll compare my test results with
> > yours and try to tackle some of the failing cases.
> 
> looks very promising
> 
> -- ,
> Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/

--Geoff

Received on Tuesday, 1 April 2003 16:37:48 UTC