RE: enforcing the prohibition



> -----Original Message-----
> From: Axel Polleres [mailto:axel.polleres@deri.org]
> Sent: 23 May 2009 01:17
> To: Pat Hayes
> Cc: Eric Prud'hommeaux; Seaborne, Andy; Sandro Hawke; public-rdf-text@w3.org
> Subject: Re: enforcing the prohibition
> 
> Pat Hayes wrote:
> >
> > On May 22, 2009, at 1:31 PM, Axel Polleres wrote:
> >
> >> Maybe I missed that in the thread, but as for defining D-entailment
> >> for SPARQL, we should be fine, because we can restrict BGP matching
> >> extension accordingly, right?  

Yes - that's the clause about the scoping graph can only contain current-RDF-style literals with no use of rdf:PlainLiteral as a datatype.

> >> We can just say that graphs with
> >> explicit rdf:PlainLiteral typed literals aren't well-formed.

No, if you mean tehthing being queried with the BGP - the restriction should apply to the boundary of SPARQL to the entailment regime.  The scoping graph not the graph being queried.  It's quite reasonable that the queried graph contain rdf:PlainLiteral.  It may not be an RDF graph; consider SPARQL/OWL or a graph which does grok rdf:PlainLiteral.  What matters is the form of the results, not what's in the OWL/D-entailment engine.

 Andy


> >
> > We can say that, yes, but there is nothing in the current RDF or SPARQL
> > specs that say this.
> 
> just wanted to make sure with you that this is a feasible approach...
> 
> > So what should a conforming SPARQL/RDF engine do,
> > if it comes across one? Apart from reporting it to the OWL/RIF militia,
> > that is. That is why I think having a named 'convention' that engines
> > can say they support, or not, is useful. An engine which does can flag
> > this as an error with a clear conscience, and its owners can cite the
> > relevant W3C document when challenged, and nobody has to refer to OWL or
> > RIF (inviting the response: so what, I'm not using those, just RDF...)
> > Note, just saying that you support {rdf:text}-entailment isn't going to
> > be enough.
> 
> ... just as SPARQLOWL entailment migt refuse graphs containing graphs
> that comprise incomplete OWL axioms (e.g. having malformed RDF lists, etc.)
> 
> >
> > Pat
> >
> >>
> >> Axel
> >>

Received on Saturday, 23 May 2009 15:57:55 UTC