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Requirement 3.4 Subgraph Results - another attempt.

From: Seaborne, Andy <andy.seaborne@hp.com>
Date: Fri, 7 May 2004 14:08:23 +0100
Message-ID: <E864E95CB35C1C46B72FEA0626A2E808031A907D@0-mail-br1.hpl.hp.com>
To: RDF Data Access Working Group <public-rdf-dawg@w3.org>

Let me try to word a requirement that is less specific about detail, and
more about intent.

Proposal -------------

3.4 Subgraph Results

It must be possible to select an entailed subgraph of a queried graph.  In
this case, the results are themselves an RDF graph.

----------------------

I used "entailed" - is that right usage Pat? - to mean an RDF subgraph of
triples that are also true given the original ground facts given any level
of inference the implementation cares to have.  I left out any mention of
RDFS, OWL etc.  There are many characteristics of a source a client might be
interested in (speed, reliability, inference capability) and it is out of
scope to describe sources.  I tried to say as little as possible about the
returned graph except to note that it is not the only form of results we
will provide.

As such, this is little more than the statements in the the charter where it
says:

] 1. Scope of RDF Data Access Working Group
.... 
] The principal task of the RDF Data Access Working Group is to
] gather requirements and to define an HTTP and/or SOAP-based
] protocol for selecting instances of subgraphs from an RDF graph.
....

] 1.8 Derived Graphs
] The working group must recognize that RDF graphs are often
] constructed by aggregation from multiple sources and through
] logical inference, and that sometimes the graphs are never
] materialized. Such graphs may be arbitrarily large or infinite.

Significant points:

1/ It says "selecting instances of subgraphs"

2/ It says "RDF Graph" in section 1.
That's defined in RDF Concepts [1]: "An RDF graph is a set of RDF triples"
Section 1.8 extends that to "construction ... through logical inference". 

	Andy

[1] http://www.w3.org/TR/2004/REC-rdf-concepts-20040210/#section-rdf-graph
Received on Friday, 7 May 2004 09:08:52 GMT

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