Re: OWL-S process preconditions

> The current frontrunner is to represent conditions as literals, either
> XML literals or some other kind.  An attribute of a condition is its
> logical language.  Example:
> 
>    <owls:AtomicProcess>
>       <owls:hasPrecondition>
> 	<owls:Expression expressionLanguage="&swrl;#SWRL"
> 	                 rdf:parseType="Literal">
>            <ruleml:body rdf:parseType="Collection">
> 	      <swrl:individualPropertyAtom>
> 		 <swrl:propertyPredicate rdf:resource="creditCardAuth"/>
> 		 <swrl:argument1 rdf:resource="#cc"/>
> 		 <swrl:argument2 
rdf:datatype="&xsd;#string">Yes</swrl:argument2>
> 	      </swrl:individualPropertyAtom>
>            </ruleml:body rdf:parseType="Collection">
> 	</owls:Expression>
>       </owls:hasPrecondition>
>    </owls:AtomicProcess>
> 
> The reason to use literals is to "hide" the RDF from the main RDF
> parser.  What a knowledgeable Owl-S parser must actually do is
> re-parse the hidden RDF chunks later, when it's possible to do
> appropriate substitutions.  In the example above, the
> individualPropertyAtom is not really about the variable "#cc"; it's
> about the _value_ of that variable in some context.  When that value
> is available, the RDF can be reprocessed to yield a statement about
> the authorization status of that credit card.

If I understand your example correctly, it's equivalent to:
creditCardAuth(?cc, Yes)

Incidentally, should this atom be a Datavalued Property Atom, as the range is a 
data value?

Cheers,
Dónal

Received on Saturday, 19 June 2004 09:34:25 UTC