Re: Proposed change to the OWL-2 Direct Semantics entailment regime

On 30 Nov 2010, at 15:51, Lee Feigenbaum wrote:

> On 11/30/2010 9:49 AM, Enrico Franconi wrote:
>> I repeat myself: *any* OWL-QL or OWL-EL implementation by design incorporates BGPs with OWL Direct Semantics in the manner I'm proposing. Not having BGPs in the manner I'm proposing would force them not to adopt SPARQL for their systems.
> 
> Thanks, Enrico.
> 
> Birte and Bijan -- if all current SPARQL implementations that incorporate OWL QL or OWL EL semantics behave in this way, wouldn't we be facing a significant implementation cost to keep the spec "as is"? i.e. wouldn't we be asking all current SPARQL-OWL implementations to change their behavior?

My answer to this question is: YES. If they want to be compliant, they would have to change their behaviour (to deal with bnodes in the data, to returns bnodes, and to rewrite all their optimisation strategies and heuristics).
--e.

> 
> Lee (has a feeling he is not understanding something here)
> 
> 
>> --e.
>> 
>> 
>> On 30 Nov 2010, at 15:44, Lee Feigenbaum wrote:
>> 
>>> On 11/30/2010 9:37 AM, Enrico Franconi wrote:
>>>> Any OWL-QL or OWL-EL implementation by design incorporates OWL Direct Semantics in the manner I'm proposing.
>>>> I'm too lazy to list them all.
>>>> Many of them are used in real world applications such as banking, database integration, medical applications, etc.
>>>> cheers
>>>> --e.
>>> 
>>> Hi Enrico,
>>> 
>>> Thanks. I'm specifically interested in anyone doing SPARQL in the context of OWL direct semantics. Are you aware of any implementations doing this?
>>> 
>>> thanks,
>>> Lee
>>> 
>>>> 
>>>> On 30 Nov 2010, at 15:29, Lee Feigenbaum wrote:
>>>> 
>>>>> On 11/30/2010 9:20 AM, Enrico Franconi wrote:
>>>>>> 
>>>>>> Be surprised: the academic, industry, and system people working on OWL-QL-based systems are already very upset by the limitation of the current version of the standard, and asked me to discuss the matter with the group.
>>>>>> 
>>>>>>> Finally, since it's so well defined and understood its not like if it becomes suddenly known useful that there'd be any barrier to implementations picking it up.
>>>>>> 
>>>>>> I fail to understand this argument. Why are we standardising something, if it is already well known? Maybe to facilitate interoperability of acknowledged technologies? :-)
>>>>> 
>>>>> Hi Enrico,
>>>>> 
>>>>> Are there existing implementations of SPARQL that incorporate OWL Direct Semantics in the manner you're proposing?
>>>>> 
>>>>> Bijan, Birte -- do the systems that you're familiar with currently implement SPARQL with OWL Direct Semantics in the manner that's in the current entailment document, or is it not yet implemented at all?
>>>>> 
>>>>> thanks,
>>>>> Lee
>>>> 
>>>> 
>>>> 
>> 
>> 
> 

Received on Tuesday, 30 November 2010 15:00:56 UTC