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comments / questions on the SHACL abstract syntax document

From: Iovka Boneva <iovka.boneva@univ-lille1.fr>
Date: Tue, 23 Aug 2016 12:25:55 +0200
To: public-rdf-shapes@w3.org
Message-ID: <5b4c999e-9cc9-14ba-9dc7-5864dabdcc0f@univ-lille1.fr>
1) is a difference between the SHACL abstract syntax and the SHACL 
specification
2) is a potential error in both SHACL abstract syntax and SHACL 
specification.

Here above,
"SHACL abstract syntax" refers to 
http://w3c.github.io/data-shapes/shacl-abstract-syntax/ Editor's Draft 
23 August 2016
"SHACL Specification" refers to https://www.w3.org/TR/shacl/ Working 
Draft 14 August 2016


1)
ISSUE 2 in SHACL abstract syntax Section 5.1.2
http://w3c.github.io/data-shapes/shacl-abstract-syntax/#RDFtermequivalence

The 'hasValue' parameter is not a particular case of the 'in' parameter, 
contrary to what is suggested by ISSUE 2.
As far as I understand the SHACL specification:
- 'hasValue' tests whether one of the value nodes has the specified 
value, and disregards the other value nodes.
- 'in' tests whether all the value nodes have a value that is included 
in the set

The 'hasValue' parameter differs from most of the other parameters with 
this regard, which can be misleading to users. So the question whether 
this parameter should be treated in the same way as the other parameters 
is of independent interest, imho.


2)
In Section 5.1.6
http://w3c.github.io/data-shapes/shacl-abstract-syntax/#Comparisonwithsiblingproperty

The semantics of comparison with specified property is incomplete: it is 
undefined in some cases.
It does not say what happens if there are several value nodes with which 
to compare.

For instance, constraint :

<IssueShape>sh:property  [ sh:predicate ex:submittedOn; sh:lessThan ex:reproducedOn ]  .

Graph

<issue1>ex:submittedOn  "2016-07-08T10:23:45Z"^^xsd:dateTime  ;
          ex:reproducedOn  "2016-07-08T13:53:00Z"^^xsd:dateTime  ;
ex:reproducedOn  "2016-07-08T09:53:00Z"^^xsd:dateTime  .

Does the test pass or fail ?

As far as I can see, the SHACL specification il also incomplete in this 
case.



-- 
Iovka Boneva
Associate professor (MdC) Université de Lille
http://www.cristal.univ-lille.fr/~boneva/
+33 6 95 75 70 25
Received on Tuesday, 23 August 2016 10:33:22 UTC

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