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Re: when is a node a class, when is a node a shape, when is a node an instance of a class

From: Holger Knublauch <holger@topquadrant.com>
Date: Fri, 15 Jan 2016 14:16:37 +1000
To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>, public-data-shapes-wg@w3.org
Message-ID: <569872A5.7090106@topquadrant.com>
On 15/01/2016 12:14 PM, Peter F. Patel-Schneider wrote:
> That is not sufficient because there are several sources of information input
> into SHACL.  For example, is a node an instance of a class for scoping if the
> rdf:type triple is in the shapes graph, or do only triples in the data graph
> count for this?

Ok, these questions need to be answered on a case-to-case basis. For 
your specific issue above (if I understand it correctly), I have added a 
clarifying sentence to state that the triples must be in the data graph.

https://github.com/w3c/data-shapes/commit/de401e2c411b616bb821fd7d313cebad0835d4c5

Which other places would require such clarifications?

Thanks,
Holger


>
> peter
>
>
> On 01/14/2016 03:14 PM, Holger Knublauch wrote:
>> The spec currently has section 1.1 where we state that certain terms from RDFS
>> are used with slightly different meaning in the SHACL spec. Maybe, to satisfy
>> the issue you raise below, we could expand this section a little bit to
>> clarify that "being in instance" means something like
>>
>> ASK {
>>      $type rdfs:subClassOf* ?class .
>>      $instance a ?class .
>> }
>>
>> Then, "being a class" means $type=rdfs:Class and "being a shape" means
>> $type=sh:Shape.
>>
>> Would this help?
>>
>> Holger
>>
>>
>> On 15/01/2016 2:09 AM, Peter F. Patel-Schneider wrote:
>>> SHACL currently depends on the answers to several class-based questions,
>>> including
>>> - when is a node a class
>>> - when is a node a shape
>>> - when is a node an instance of a class
>>> but how these are determined is not completely spelled out in the SHACL
>>> documment.
>>>
>>> I think that there needs to be a complete definition of these relationships in
>>> the SHACL document and test cases to back up the definition.
>>>
>>> peter
>>>
>>
Received on Friday, 15 January 2016 04:17:16 UTC

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