- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Thu, 5 Feb 2015 11:19:00 -0500
- To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
- Cc: Jose Emilio Labra Gayo <jelabra@gmail.com>, Holger Knublauch <holger@topquadrant.com>, "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
Hi Peter,
> On 5 Feb 2015, at 10:38, Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:
>
> How does one include anything in a class definition in RDF or RDFS?
Well, one could write it in prose text into the specification that defines the class.
One could also write it into an rdfs:comment or skos:definition in the RDFS file that defines the class.
Or, if one has appropriate vocabulary, one could say it directly in triples in that RDFS file.
> What is a class definition in RDF or RDFS?
I’ll answer by giving an example. Here’s the definition of the class qb:Dataset:
http://www.w3.org/TR/void/#dataset
A pitifully small part of that definition is also written down in the associated RDFS file here:
[[[
void:Dataset a rdfs:Class, owl:Class;
rdfs:label "dataset";
rdfs:comment "A set of RDF triples that are published, maintained or aggregated by a single provider." .
]]]
> What does it mean to include a shape in a class definition?
Here’s what I mean when I use these words:
1. The shape is published in the RDFS file that defines the class (assuming shapes can be expressed in triples).
2. If an RDF graph G includes a statement that claims a resource X to be a member of the class, but the description of X in G doesn’t fit the shape, then G is “invalid”, for some to-be-defined notion of “validity”. The important thing is that a validator can detect the condition.
3. Maybe it also means that G is “shape-inconsistent”.
Best,
Richard
>
> peter
>
>
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Received on Thursday, 5 February 2015 16:19:27 UTC