Re: ruleml and RDF

> [Xue Laos]
> hello, RuleML is xml-based. till now, why we can not define rule in pure
> RDF? SWRL is still focusing on DL. xjx

I don't understand the bit about "SWRL is still focusing on DL."
Every attempt to encode rules in "pure RDF" ends up concealing the RDF
triples somehow.  For instance, the SWRL rule

     parent(?x,?y) & brother(?y,?z) => uncle(?x,?z)

would seem to contain the three triples

      ?x parent ?y
      ?y brother ?z
      ?x uncle ?z

but these become "individualPropertyAtoms" in the RDF encoding:

<swrl:Variable rdf:ID="x1"/>
<swrl:Variable rdf:ID="x2"/>
<swrl:Variable rdf:ID="x3"/>
<ruleml:Imp> 
  <ruleml:body rdf:parseType="Collection">
    <swrl:individualPropertyAtom> 
      <swrl:propertyPredicate rdf:resource="&eg;hasParent"/> 
      <swrl:argument1 rdf:resource="#x1" />
      <swrl:argument2 rdf:resource="#x2" />
    </swrl:individualPropertyAtom>
    <swrl:individualPropertyAtom> 
      <swrl:propertyPredicate rdf:resource="&eg;hasBrother"/> 
      <swrl:argument1 rdf:resource="#x2" />
      <swrl:argument2 rdf:resource="#x3" />
    </swrl:individualPropertyAtom>
  </ruleml:body>
  <ruleml:head rdf:parseType="Collection"> 
    <swrl:individualPropertyAtom> 
      <swrl:propertyPredicate rdf:resource="&eg;hasUncle"/> 
      <swrl:argument1 rdf:resource="#x1" />
      <swrl:argument2 rdf:resource="#x3" />
    </swrl:individualPropertyAtom>
  </ruleml:head> 
</ruleml:Imp> 

Is the absence of the actual triples bothering you?  If so, you're out
of luck, because there's really no good way to put them in.

-- 
                                   -- Drew McDermott
                                      Yale Computer Science Department