Re: on values

The way I read it is as follows:

A value of a property could potentially be an IRI or a literal or a blank node. This is what follows from:

>>> The values of a property p for a node n in an RDF graph are the objects of
>>> the triples in the graph that have n as subject and p as predicate.

The value of sh:targetNode is either an IRI or a literal.

Since the second statement “narrows the scope” from a more general definition of what a property value is to a more specific definition of what a value of sh:targetNode is, I do not see any contradictions. 

However, if this statement is not true and a value of sh;targetNode could be a blank node, I see your point.

> On Dec 3, 2016, at 1:13 PM, Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:
> 
> "Each value of sh:targetNode is either an IRI or a literal." appears to be
> quite clear, particularly with the definition of value in the doducment.  The
> problem is that it is not the case that each value of sh:targetNode is either
> an IRI or a literal.
> 
> peter
> 
> 
> On 12/03/2016 09:33 AM, Irene Polikoff wrote:
>> Peter, I read the entire message first time you sent it.
>> 
>> I didn't understand what problem you are seeing. This is why I asked for clarification.
>> 
>> If the last two sentences don't reflect a problem by themselves, then is the problem in that the following doesn't make the subject clear?
>> 
>> <Each value of sh:targetNode is either an IRI or a literal.>
>> 
>> or something else?
>> 
>> Sent from my iPhone
>> 
>>> On Dec 3, 2016, at 11:44 AM, Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:
>>> 
>>> The entire message reads:
>>> 
>>> 
>>> ***************************
>>> 
>>> There is a lot of wording like
>>> Each value of sh:targetNode is either an IRI or a literal.
>>> in Shapes Constraint Language (SHACL) W3C Editor's Draft 02 December 2016,
>>> where the relevant definition of value in the document appears to be
>>> The values of a property p for a node n in an RDF graph are the objects of
>>> the triples in the graph that have n as subject and p as predicate.
>>> 
>>> This statement is not universally true, such as in the RDF graph
>>> _:a sh:targetNode _:b .
>>> 
>>> Presumably the statement is meant to be interpreted in some context, but
>>> there is no context given in the neighbourhood of the statement.
>>> 
>>> 
>>> Peter F. Patel-Schneider
>>> Nuance Communications
>>> 
>>> ****************************
>>> 
>>> The referent of the "This statement" is
>>> Each value of sh:targetNode is either an IRI or a literal.
>>> which is not true  in the RDF graph provided.
>>> 
>>> peter
>>> 
>>> 
>>> 
>>>> On 12/02/2016 11:02 PM, Irene Polikoff wrote:
>>>> Peter, could you please explain why you say that the statement is not true.
>>>> 
>>>> In your example, _:a is a subject (node n), sh:targetNode is a predicate
>>>> (property p) and _:b is the object (the value).
>>>> 
>>>>> On Dec 2, 2016, at 10:15 PM, Peter F. Patel-Schneider
>>>>> <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> wrote:
>>>>> 
>>>>> The values of a property p for a node n in an RDF graph are the objects of
>>>>> the triples in the graph that have n as subject and p as predicate.
>>>>> 
>>>>> This statement is not universally true, such as in the RDF graph
>>>>> _:a sh:targetNode _:b .
>>>>

Received on Saturday, 3 December 2016 18:41:05 UTC