- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Sat, 25 Oct 2014 18:32:21 -0700
- To: Irene Polikoff <irene@topquadrant.com>, 'Holger Knublauch' <holger@topquadrant.com>, public-data-shapes-wg@w3.org
On 10/25/2014 05:33 PM, Irene Polikoff wrote:
> Peter,
>
> You may be envisioning something much more complex than what it really is.
It does seem so, but there has been lots of talk about OWL. There has been
quite a bit of work on constraints in OWL, and the situation there is very
complex.
OWL is not just a syntax, it's a state of mind, and it seems that OWL and SPIN
don't share this state of mind.
> As mentioned below, rdfs:subClassOf axioms are the only axioms that are considered.
So it seems that SPIN and RDFS don't even share a state of mind then.
> < SPIN only looks at rdfs:subClassOf, which is used by both RDFS and OWL.
> There are no dependencies on OWL at all, except that owl:imports should be observed.>
>
> Thus, no constraints would be executed for your first example because constraints in the example are associated with classes B and C, there are no subclass relationship between these classes and class A and the only instance we have is a member of class A.
>
> If the model included triples:
>
> :A rdfs:subClassOf :B
> :A rdfs:subClassOf :C
>
> Then both constraints would be executed - for B and for C. How these triples got added to the model is outside of the area of concern for SPIN constraints checking. For example, if you have a model that is rich in OWL axioms, you could run it through a DL reasoner before checking for the constraint violations.
>
> As an aside, there is no need to say in the WHERE clause {?this a :B} or {?this a :C}. Using ?this already assumes that we are talking about a member of the class constraint is associated with.
>
> Irene
>
peter
Received on Sunday, 26 October 2014 01:32:51 UTC