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Re: divergence in the definition of sh:minCount

From: Irene Polikoff <irene@topquadrant.com>
Date: Mon, 26 Sep 2016 16:48:54 -0400
To: Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>, "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
CC: "public-rdf-sha." <public-rdf-shapes@w3.org>
Message-ID: <D40F0174.B7389%irene@topquadrant.com>
I thought what Peter is saying that even if the count is four, there are
only two nodes in the graph in this example, so this is a language/wording
issue.

Irene

From:  Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>
Date:  Monday, September 26, 2016 at 3:11 PM
To:  "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
Cc:  "public-rdf-sha." <public-rdf-shapes@w3.org>
Subject:  Re: divergence in the definition of sh:minCount
Resent-From:  <public-rdf-shapes@w3.org>
Resent-Date:  Mon, 26 Sep 2016 19:12:00 +0000

Maybe it is something very obvious but I still cannot see it.

however, I improved the wording for the property path value nodes. It was
using subject and object which was not correct, shapes can use also literals
as focus nodes
https://github.com/w3c/data-shapes/commit/f1d525b82ce8a74092826e768159db6012
70033a

On Mon, Sep 26, 2016 at 6:55 PM, Peter F. Patel-Schneider
<pfpschneider@gmail.com> wrote:
> You mean that you got back 4 results when running the SPARQL query.  That's
> different from "the number of value nodes", which is my point.
> 
> peter
> 
> 
> On 09/26/2016 12:30 AM, Dimitris Kontokostas wrote:
>> > Hi Peter,
>> >
>> > I tried your example and I got 4 "value nodes" back which is in line with
>> the
>> > duplicate value node comment above.
>> >
>> > I am trying to see the problem here, is it the following wording from
>> section 4?
>> > "For property constraints that have a sh:path the value nodes are the
>> objects
>> > in the data graph that can be reached by following the given property path
>> > starting with the focus node as subject based on the evaluation rules
>> defined
>> > by SPARQL 1.1"
>> >
>> > I think this can be improved but I cannot see if there is a wrong
>> definition
>> > there.
>> >
>> > Thanks,
>> > Dimitris
>> >
>> > On Sun, Sep 25, 2016 at 12:43 AM, Peter F. Patel-Schneider
>> > <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> wrote:
>> >
>> >     Even if you "count all nodes, even duplicates", there is still a
>> violation in
>> >
>> >     Data:
>> >       :john :child :bill .
>> >       :john :son :bill .
>> >       :john :child :mary .
>> >       :john :daughter :mary .
>> >
>> >     Shape
>> >       s:s1 rdf:type sh:Shape ;
>> >         sh:targetNode :john ;
>> >         sh:property [ sh:path [ sh:alternativePath ( :child :son :daughter
>> ) ] ;
>> >                       sh:minCount 3 ] .
>> >
>> >     If something other than "A validation result must be produced if the
>> number of
>> >     value nodes is less than the value of sh:minCount." is desired then
>> this
>> >     wording can no longer be used, particularly given the wording about
>> path-based
>> >     property constraints at the beginning of Section 4.
>> >
>> >     peter
>> >
>> >
>> >
>> >     On 09/24/2016 07:12 AM, Dimitris Kontokostas wrote:
>>> >     > Hi Peter,
>>> >     >
>>> >     > is this about the fact that property paths might return duplicate
>>> value nodes
>>> >     > or something else?
>>> >     > In this case, we count all nodes, even duplicates for cardinality
>>> restrictions
>>> >     >
>>> >     > Thanks,
>>> >     > Dimitris
>>> >     >
>>> >     > On Fri, Sep 23, 2016 at 9:17 PM, Peter F. Patel-Schneider
>>> >     > <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>
>> >     <mailto:pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>>> wrote:
>>> >     >
>>> >     >     The textual and SPARQL definitions of sh:minCount do not align
when
>> >     paths
>>> >     >     are allowed.
>>> >     >
>>> >     >
>>> >     >     A validation result must be produced if the number of value >>>
nodes is
>> >     less
>>> >     >     than the value of sh:minCount.
>>> >     >
>>> >     >     SELECT $this
>>> >     >     WHERE {OPTIONAL {$this $PATH ?value .}}
>>> >     >     GROUP BY $this
>>> >     >     HAVING (COUNT(?value) < $minCount)
>>> >     >
>>> >     >
>>> >     >
>>> >     >     Peter F. Patel-Schneider
>>> >     >     Nuance Communications
>>> >     >
>>> >     >
>>> >     >
>>> >     >
>>> >     > --
>>> >     > Dimitris Kontokostas
>>> >     > Department of Computer Science, University of Leipzig & DBpedia
>>> Association
>>> >     > Projects: http://dbpedia.org, http://rdfunit.aksw.org,
>> >     http://aligned-project.eu
>>> >     > Homepage: http://aksw.org/DimitrisKontokostas
>> >     <http://aksw.org/DimitrisKontokostas>
>>> >     > Research Group: AKSW/KILT http://aksw.org/Groups/KILT
>>> >     >
>> >
>> >
>> >
>> >
>> > --
>> > Dimitris Kontokostas
>> > Department of Computer Science, University of Leipzig & DBpedia Association
>> > Projects: http://dbpedia.org, http://rdfunit.aksw.org,
>> http://aligned-project.eu
>> > Homepage: http://aksw.org/DimitrisKontokostas
>> > Research Group: AKSW/KILT http://aksw.org/Groups/KILT
>> >
> 



-- 
Dimitris Kontokostas
Department of Computer Science, University of Leipzig & DBpedia Association
Projects: http://dbpedia.org, http://rdfunit.aksw.org,
http://aligned-project.eu
Homepage: http://aksw.org/DimitrisKontokostas
Research Group: AKSW/KILT http://aksw.org/Groups/KILT
Received on Monday, 26 September 2016 20:49:34 UTC

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