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Re: property paths three more test cases pp13, pp14, pp15

From: Steve Harris <steve.harris@garlik.com>
Date: Tue, 21 Dec 2010 11:12:28 +0000
Cc: "Andy Seaborne" <andy.seaborne@epimorphics.com>, "SPARQL Working Group" <public-rdf-dawg@w3.org>
Message-Id: <E5CF19C2-711C-4DDE-82F0-098751A48462@garlik.com>
To: Axel Polleres <axel.polleres@deri.org>
On 2010-12-20, at 17:23, Axel Polleres wrote:

> Steve,
> 
> I added a new use case pp16 along the lines you suggest, see details below.
> 
> On 20 Dec 2010, at 16:46, Steve Harris wrote:
> 
>> I think pp14 would be more enlightening if the pp14.ttl included a disconnected foaf:knows graph, and some triples using another predicate. Something like:
>> 
>> @prefix : <http://example.org/> .
>> @prefix foaf: <http://xmlns.com/foaf/0.1/> .
>> 
>> :a foaf:knows :b .
>> :b foaf:knows :c .
>> :d foaf:knows :e .
>> :f foaf:name "test" .
>> :a foaf:homepage :h .
>> 
>> Even after Axel's proposed changes I find the wording a bit impenetrable, though admittedly I haven't had time to study the algebra.
>> 
>> Axel, can you tell mw what results you'd expect from pp14.rq with that data?
>> 
> 
> your data returns, according to my understanding of the algebra:
> 
> -------------------
> | X      | Y      |
> ===================
> | :a     | :a     |
> | :a     | :b     |
> | :a     | :c     |
> | :b     | :b     |
> | :b     | :c     |
> | :c     | :c     |
> | :d     | :d     |
> | :d     | :e     |
> | :e     | :e     |
> | :f     | :f     |
> | :h     | :h     |
> | "test" | "test" |
> -------------------

OK, thanks. Intuitively I find the :e/:e, :f, :h, and "test" results odd, but I've not given enough time to trying to understand the usecases.

> I would, BTW, rather keep the simple use case pp14 "as is", and added a more complex one having your extension, as well as
> duplicate paths and cycles as a  separate new use case:

Yes, agreed.

- Steve

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Received on Tuesday, 21 December 2010 11:13:03 GMT

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