- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Sat, 20 Dec 2014 08:33:28 -0800
- To: RDF Data Shapes Working Group <public-data-shapes-wg@w3.org>
I'm still having a hard time trying to figure out how some of the proposed solutions work. I understand this for OWL constraints and SPIN, but none of the others. I don't think that I am the only working group member in this situation. I would find it very useful if there was a simple description of the basic operation of each proposed solution, condensed down into something that can be easily digested. For example here is a version for OWL constraints: OWL constraints verifies an RDF graph against a document containing constraints, each of which being an OWL axiom. The verification succeeds if each axiom is true in the RDF graph under the closed world and unique names assumption. A typical axiom is of the form SubClassOf(class description). For example, SubClassOf(person ObjectExactCardinality(2 child)) requires that each instance of child is the subject of precisely two different triples with predicate child. Here is part of a version for SPIN: SPIN verifies an RDF graph against a document containing classes connected to constraints in the form of SPARQL queries. The verification succeeds if each SPARQL query with ?THIS bound to instances of the class produces no results when run on the RDF graph. The query does not have to contain a ?THIS variable, thus allowing global constraints. For example, person SPIN:ask "SELECT ?THIS WHERE ... ?THIS ... child ... GROUP BY ... COUNT ... <= 2 ..." [FIX THIS] requires that each instance of person is the subject of at most two different triples with predicate child. Could working group members knowledgeable about the other proposed solutions produce something similar for them? peter
Received on Saturday, 20 December 2014 16:33:57 UTC