Re: Semantic of the language

Lee,

Good question! I think Marcelo would be the best to answer that question.
I'm not aware of all the new additions to SPARQL 1.1. We need to prove that
all the new additions can be represented in non recursive safe datalog. If
so.. we are good to go :)

Juan Sequeda
+1-575-SEQ-UEDA
www.juansequeda.com


On Sun, Mar 14, 2010 at 3:14 PM, Lee Feigenbaum <lee@thefigtrees.net> wrote:

> Hi Juan,
>
> Thanks for the references; I'll try to read through the papers. Do you know
> if the new additions in SPARQL 1.1 change the expressivity of the language
> in any significant way for this discussion?
>
> Lee
>
>
> On 3/14/2010 2:46 PM, Juan Sequeda wrote:
>
>> Hi everybody,
>>
>> Last telcon we said that we were going to talk about the semantics of
>> the language.
>>
>> Hopefully you all have the chance to look at these two papers:
>>
>> [1] The Expressive Power of SPARQL
>> http://www.dcc.uchile.cl/~cgutierr/papers/expPowSPARQL.pdf
>>
>> [2] Translating SQL Applications to the Semantic Web
>> http://userweb.cs.utexas.edu/~jsequeda/sql2sw_dexa2008.pdf
>>
>> [1] states that SPARQL and non-recursive safe Datalog have the same
>> expressive power. [2] shows FOL rules, which can be implemented in
>> Datalog in order to automatically generate a rdf schema or owl ontology
>> from a rdb schema. There have been several concerns that the mapping
>> language shouldn't be more expressive than SPARQL. Given this previous
>> work, if we define the mapping language based on non-recursive safe
>> datalog (as shown in [2]), then we can assure that it will have the same
>> expressive power of SPARQL [1]. Once we define the semantics, organizing
>> the syntax should be straightforward.
>>
>> Looking forward to our conversation on tuesday.
>>
>> Juan Sequeda
>> +1-575-SEQ-UEDA
>> www.juansequeda.com <http://www.juansequeda.com>
>>
>