Re: Attempt to use Owl rule language to express preconditions in Congo

Drew McDermott wrote:

>    [Drew McDermott]
>    > Here's how I would change it:
>    > 
>    >    <process:Formula>
>    >        <process:conjuncts rdf:parseType="Collection">
>    >            <owl:individualPropertyAtom>
>    >                    <owl:propertyPredicate 
>    >                               rdf:resource="&congoUserProfile;accountExists/>
>    >                    <owl:argument1 rdf:about="#AcctID" />
>    >                    <owl:argument2 rdf:about="#Password" />
>    >            </owl:individualPropertyAtom>   
>    >            <owl:individualPropertyAtom>
>    >                    <owl:propertyPredicate 
>    >                                rdf:resource="&congoUserProfile;creditExists/>
>    >                    <owl:argument1 rdf:about="#AcctID" />
>    >                    <owl:argument2 rdf:about="#CreditCardNumber" />
>    >            </owl:individualPropertyAtom>   
>    >        </process:conjuncts>
>    >    </process:Formula>
> 
>    [David Martin]
>    I believe the above is equivalent to an Horrocks/Patel-Schneider rule 
>    with an empty antecedent, and the 2 property atoms in the consequent. 
>    If that is true, perhaps we should just express it that way for now, so 
>    as to avoid defining our own Formula class which probably will be 
>    supplanted later.
> 
>    I also wonder if Ian and Peter (and the joint committee) have any plans 
>    to define something like Formula (or at least "ConjunctiveFormula"), so 
>    that one can write non-rule formulas a little more conveniently.
> 
> I hope that OWL Rules, or something a lot like it, is going to become
> the standard.  (Assuming we can't get what's really needed, which is
> to introduce non-asserted contexts into RDF.)  It would be very easy
> to switch DRS over to the OWLR vocabulary, thus making it a
> downward-compatible superset of OWL Rules.  Since OWL Rules gets
> variables right, and encodes atomic formulas right, it would be very
> easy to add explicit quantifiers and a richer zoo of atomic formula
> types.
> 
> Since OWL Rules is not the standard now, I don't think we gain
> anything by expressing a Formula as a rule with a missing antecedent.

Would it perhaps make sense, then, to define Formula in the drs 
namespace (or use whatever term drs already uses for formulas), rather 
than putting this new thing in the process namespace?

Regards,
David

> 
>                                              -- Drew
>

Received on Monday, 10 November 2003 21:35:03 UTC