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Re: ShEx relation to SPIN/OWL

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Thu, 10 Jul 2014 12:34:59 -0700
Message-ID: <53BEEAE3.2040402@gmail.com>
To: Eric Prud'hommeaux <eric@w3.org>
CC: public-rdf-shapes@w3.org
On 07/10/2014 11:58 AM, Eric Prud'hommeaux wrote:
> * Peter F. Patel-Schneider <pfpschneider@gmail.com> [2014-07-10 09:17-0700]

[...]

>>
>>
>> For example, you can recast the above example as something like
>>    DayCare = all :patron Patron & all :aide Aide & E :patron & E :aide
>>    Patron = all :hasChild Child & [1-50] :hasChild &
>>             all :creditCardNumber xsd:string & E :crediCardNumber
>>    Aide = all :hasChild Child & [,2] :hasChild
>> You then model-check the minimal model of the data and any RDFS
>> ontology used in the data against these OWL definitions.
>>
>> This actually succeeds, because there is no starting point and no
>> explicit typing in the data.  If you either add that <GacyDayCare>
>> rdf:type DayCare to the data or have a requirement that some node
>> matches <GacyDayCare> then you get a failure because Sue doesn't
>> match Patron.
>
> How does Sue fail to match Patron, is it because she fails a minimum
> cardinality constraint on :creditCardNumber? If so, I expect you've
> added NAF to OWL. Is the system doing type inference but not inferring
> e.g. that Sue has a credit card number?

The minimal model construction is a sort of closure, which is vaguely related 
to negation as failure (although there is no failure involved).  Model 
checking does not do inference, it just checks that the model satisfies the 
formulae/definitions/constraints.

> What I'm getting at is that a system that provides practical
> validation of business (or scientific, or clinical) rules isn't
> trivially available from OWL. Historically, there have been three
> deployed systems filling this void: Dublin Core Application Profiles,
> post-submission developments of spin:constraint, and OSCL Resource
> Shapes. The last half year has seen three or four implementations of
> ShEx, in part for the compact syntax (ShExC) and in part for the
> expressivity. All of this time, RDF has attracted people with an eye
> towards open world, far-sighted data integration, but has not offered
> a serious alternative to XML because it offers no analogy to Relax NG
> or W3C XML Schema.

I would say that a formalism that provides practical validation of shape 
constraints is trivially available from RDFS and OWL.  Whether this provides 
business rules is a separate issue, of course.  As well, a formalism is not a 
system.   (Consider the vast difference between first-order reasoners and 
first-order model checkers, for example.)

peter
Received on Thursday, 10 July 2014 19:35:32 UTC

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