Re: Proposed Resolution for Issue 42

Thinking quickly out loud... so please correct me if I'm wrong

wouldn't we need rdfs:range triples for the case of reference triples:

<Student/id=1> <enrolled> <Course/id=2>


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


On Tue, May 31, 2011 at 2:53 PM, Richard Cyganiak <richard@cyganiak.de>wrote:

> Hi Alexandre,
>
> On 31 May 2011, at 20:27, Alexandre Bertails wrote:
> >> I would agree to a proposal that maintains reversibility of the mapping
> by adding rdfs:domain triples to the properties, and does not generate
> triples for NULL values.
> >
> > I think that for the moment, we can agree on the current proposal
> > without speaking about any concrete solution, which will come later when
> > we're ready for it.
>
> No, because I'd like to know what I am agreeing to. I would likely be
> opposed to a solution that introduces a parliament of OWL into the direct
> mapping in order to work around the NULL issue.
>
> > rdfs:domain may be enough for this issue, but we may want other
> information as well.
>
> I think we all agree that rdfs:domain is *necessary*.
>
> I believe that it is also *sufficient* to reconstruct the NULLs, and have
> seen no claims to the contrary.
>
> So let's go with rdfs:domain *only* as the resolution to ISSUE-42.
>
> More schema triples may still be added to the direct mapping later on, but
> that needs to be discussed, and it can't be discussed before there's a
> proposal on the table. So I suggest treating additional schema triples as a
> different and separate issue (which someone should create in the tracker).
>
> PROPOSAL: Resolve ISSUE-42 by not creating triples for NULL values, and
> adding rdfs:domain statements to the direct mapping graph. This does not
> preclude adding more schema triples in a future resolution.
>
> Best,
> Richard
>