Re: First order logic and SPARQL

On 5 Sep 2010, at 22:48, Bob MacGregor wrote:

> My personal interest is in a query language for RDF that's easy to use, and, among other things,
> has a negation operator that is intuitive.  If SPARQL 1.1 adds a negation operator, that is good to know.
> 
> I would  be interested to learn of a datalog-with-negation implemented by translating to SPARQL,
> since datalog and its variants is IMO intuitive.   Are the results that show a mapping between
> a datalog variant and SPARQL just papers, or has someone actually implemented a Datalog-like
> front end that translates to SPARQL? 
> I'd like to see that.  Note: Axel cites a paper that translates
> in the other direction -- that's not what I'm after.

Indeed, we have implemented only the other direction, SPARQL to Datalog, as a prototype plugin for the 
dlvhex system cf. http://dlvhex-semweb.svn.sourceforge.net/viewvc/dlvhex-semweb/

Why would you need the translation of Datalog into SPARQL? That is something IMO just needed for the theoretical expressivity result, you dan't want to translate your datalog program into SPARQL and evaluate it with a sparql engine, that is likely not going to be very efficient...

Axel


> - Bob

Received on Tuesday, 7 September 2010 17:20:12 UTC