RE: is a missing triple a constraint violation?

Ralph,

you wrote:
> Did the Working Group intend to say that a model that does not
> contain a triple where one should be expected is also an
> "inconsistent model"?  If so, is it appropriate to add words
> to the specification to note that in the case of a constraint
> violation such as this an implementation might choose to infer
> the triple?  I think this would help clarify the intent of
> "inconsistent model" and help set the foundation for an
> "RDF Logic" layer to be specified.

I agree with Guha's original observation that both generative and
restrictive intepretations of the constraints are possible. It is, however,
important to note that these interpretations are very different
(semantically), and I feel uneasy about a situation where the producer (of
some RDF data) uses one interpretation but the consumer (of this data) uses
another.

For example, I (as a producer) could leave some stuff out, thinking that I
use the constraints to generate the missing triples, but then the consumer
of my data could deem it invalid because of constraint violations...

I consider this problematic. To include the additional text you are
suggesting would require us to also point out the possible conflicts arising
from different interpretations.

Regards,

	- Ora

--
Ora Lassila, <ora.lassila@nokia.com>
Research Manager
Agent Technology, Nokia Research Center / Boston
+1 (781) 993-4603 (please note new email & phone number!)