Max Expressivity of SPARQL (was... Re: Introductions: Lee Feigenbaum and Ben Szekely)

>
>
> """
> Ahmed: ericP, can you please ask Ivan also about SPARQL
> ... about the max expressivity of SPARQL because we don't want to have a
> mapping language that supports more expressivity than SPARQL
> """
>

The paper by Angles and Gutierrez [1] states that SPARQL and non-recursive
safe Datalog with negation have equivalent expressive power, and therefore
the expressiveness of SPARQL is equivalent to relational algebra.

We have represented the translation of sql schema to rdf schema/ owl in FOL
and Datalog [2].

Marcelo, correct me if I'm wrong... if we represent our mapping language in
Datalog, then we don't have to worry if it is more expressive than SPARQL...
AND.. we don't have to worry about the semantics of the language. The only
thing we would have to work on is the syntax.

[1] The Expressive Power of SPARQL
http://www.dcc.uchile.cl/~cgutierr/papers/expPowSPARQL.pdf
[2] Translating SQL Application to the Semantic Web
http://www.springerlink.com/content/mv58805364k31734/fulltext.pdf