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Re: [TF-PP] Minor comments on the current document

From: Andy Seaborne <andy.seaborne@talis.com>
Date: Mon, 04 Jan 2010 12:11:28 +0000
Message-ID: <4B41DAF0.1010507@talis.com>
To: Alexandre Passant <alexandre.passant@deri.org>
CC: "public-rdf-dawg@w3.org Group" <public-rdf-dawg@w3.org>


On 24/11/2009 12:14 PM, Alexandre Passant wrote:
> Hi,
>
> I think I missed the original announcement regarding the availability of the document in SVN, but here are some late and minor comments about it.
>
> - Shouldn't it generally use the term "inverse" instead of "reverse" ? Seems more coherent with the current terminology

"Reverse" was appealing to a more navigational view of  property paths.

As it also has support from Ivan as well, I've made the changes.

>
> - In the first table, I'd suggest, "Name of people one "foaf:knows" step away" rather that 'one "knows" steps away'

Done.

>
> - Last example of 4.1: must we read
>
>    ?x foaf:knows/^foaf:knows ?x .  (i.e. foaf:knows followed by an inverse foaf:knows)
>
> instead of
>
>    ?x foaf:knows^foaf:knows ?x .
>
> ?

These would be two ways to write the same thing.

The design follows N3 where "^" is backwards traversal and comes in 
unary and binary forms.  It does mean "/^" is the same as the binary 
inverse "^".

N3 uses "." for forward traversal where Property Path uses "/".  dot in 
prefixed names is legal in SPARQL but not in N3.

>
> - Should we also mention that PP does not provide new features to SPARQL per se, but a simpler way to write query involving paths.

Arbitrary length paths can't be matched in SPARQL.  I've added a 
sentence in the intro to this effect.

	Andy

>
> Best,
>
> Alex.
>
> --
> Dr. Alexandre Passant
> Digital Enterprise Research Institute
> National University of Ireland, Galway
> :me owl:sameAs<http://apassant.net/alex>  .
>
>
>
>
>
>
>
>
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Received on Monday, 4 January 2010 12:12:03 GMT

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