Re: Web Rule Language - WRL vs SWRL

On Jun 23, 2005, at 3:06 AM, Jos de Bruijn wrote:

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> Bijan Parsia wrote:
[snip]
>> Key is the slipping in of "ground".
>
> No. For query answering only ground entailment is relevant.\

Interesting presumption.

>>> entailments for both
>>> semantics are *equivalent* and thus the queries would return the same
>>> result.
>>
>>
>> Of course, RDF entailment includes existential generalization, so
>> that's not quite right. There seems to be more work that you need to
>> do to get what you wanted (e.g., you need to look at the semantics
>> of the query language; is the query "not" classical? how would that
>> classical not interact with the LP semantics?)
>
> The RDF language contains existentials and I'm not claiming that this
> can be done by a rule language.
> We are talking about Horn Logic and Horn Logic does not have
> existentials! I never claimed this!
> You claimed

Please point to where I claimed this.

>  that a Horn formula under FOL semantics has other ground
> entailments than a Horn formula under LP semantics and this is simply
> not true.
> I think this can conclude our discussion on this topic.
[snip]
Oh, I *quite* agree. But perhaps not for the same reasons.

Cheers,
Bijan.

Received on Thursday, 23 June 2005 13:28:15 UTC