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Re: Issue-89, proposal 3: Duplication of triples & inferencing

From: Arnaud Le Hors <lehors@us.ibm.com>
Date: Thu, 12 Dec 2013 10:20:47 -0800
To: Henry Story <henry.story@bblfish.net>
Cc: Linked Data Platform WG <public-ldp-wg@w3.org>
Message-ID: <OFF2B2DB24.CF7E658A-ON88257C3F.0063D970-88257C3F.0064C85C@us.ibm.com>
While true, it's been pointed out before, several times, that this would 
fall short of addressing the use case at hand: allowing one to define a 
container over existing data by leveraging a domain specific vocabulary.

It's this new relationship that should be inferred.
--
Arnaud  Le Hors - Software Standards Architect - IBM Software Group


Henry Story <henry.story@bblfish.net> wrote on 12/12/2013 09:27:28 AM:

> From: Henry Story <henry.story@bblfish.net>
> To: Linked Data Platform WG <public-ldp-wg@w3.org>, 
> Date: 12/12/2013 09:31 AM
> Subject: Issue-89, proposal 3: Duplication of triples & inferencing
> 
> Part 3 of Issue-89 creates a relation ldp:propertiesOnlyResource
> to allow an LDPC to point in its header to the "membership properties".
> The reason for this is to avoid so called duplication of triples.
> 
> The duplication of triples is an issue mostly for the 
> ldp:DirectContainer as is visible for a container such
> as the following
> 
> <> a ldp:DirectContainer;
>         ldp:containerResource <>;
>         ldp:containsRelation m:manages;
>     ldp:xyz <doc1>, <doc2>, <doc3> ;
>     m:manages <doc1>, <doc2>, <doc3> .
> 
> ( I am using ldp:xyz for what alexander in ISSUE-89 calls 
>   ldp:contains. You can replace it without loss here and 
>   throughout this e-mail. )
> 
> But according to the rule such as the one used in the Membership wiki 
[1]
> it would be very easy to determine the "membership triples" using only 
> the ldp:xyz relations
> 
> PREFIX ldp: <http://www.w3.org/ns/ldp#>
> 
> CONSTRUCT { ?subject ?predicate ?object }
> WHERE {
>    ?ldpc a ldp:DirectContainer;
>         ldp:containerResource ?subject;
>         ldp:containsRelation ?predicate;
> 
>    ?ldpc ldp:xyz ?document .
>    BIND (?document AS ?object)                             # the 
> POSTed resource is the member
>  } UNION {
>    ?ldpc a ldp:DirectContainer;
>         ldp:containerResource ?object;
>         ldp:containedByRelation ?predicate.                   # 
> ldp:containedByRelation is used
> 
>    ?ldpc ldp:xyz ?document .
>    BIND (?document AS ?object)
>  }
> }
> 
> In that case duplication is not a problem at all,
> since a client could just infer the "membership triples"
> from the ldp:xyz ones using that query.
> 
> On the other hand if such a rule is not true, and cannot
> be written out, then there is no duplication, since the
> "membership triples" are in fact different triples, and
> have no necessary relation to the ldp:xyz ones.
> 
> But then this does give one a good reason for having them in a
> different possibly server managed resource. 
> 
> 
> 
> 
> [1]in the Membership wiki "Determining the membership  triples to be
> added when a new member 
> is created"  http://www.w3.org/2012/ldp/wiki/
> 
Membership#Determining_the_membership_triples_to_be_added_when_a_new_member_is_created
> 
> 
> Social Web Architect
> http://bblfish.net/
> 
> 
Received on Thursday, 12 December 2013 18:21:22 UTC

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