not the negative guards alone cause pathologic examples!!!!...

Please note that Jos pathological use case

http://www.w3.org/2005/rules/wiki/Disjunctive_Information

can very similarly be modeled with comparison operators, which doesn't 
only put negative guards, but also our "convenient"
less-than-or-equal, greater-than-or-equal predicates at risk:


Document(
Prefix(ex http://example.com/example#)
Prefix(pred http://www.w3.org/2007/rif-builtin-predicate#)

Group(
ex:p(ex:a)
Forall ?x (1=2 :- And (ex:p(?x) pred:less-than(?x 5)
pred:greater-than(?x 0) ) )
)

entails:

Or ( pred:greater-than-or-equal(ex:a 5)
      pred:less-than-or-equal(ex:a 0) )


best,
Axel


-- 
Dr. Axel Polleres, Digital Enterprise Research Institute (DERI)
email: axel.polleres@deri.org  url: http://www.polleres.net/

Everything is possible:
rdfs:subClassOf rdfs:subPropertyOf rdfs:Resource.
rdfs:subClassOf rdfs:subPropertyOf rdfs:subPropertyOf.
rdf:type rdfs:subPropertyOf rdfs:subClassOf.
rdfs:subClassOf rdf:type owl:SymmetricProperty.

Received on Saturday, 27 September 2008 21:08:14 UTC