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Re: williams-01, proposal to close (20030411)

From: Graham Klyne <gk@ninebynine.org>
Date: Fri, 09 May 2003 19:57:44 +0100
Message-Id: <>
To: Brian McBride <bwm@hplb.hpl.hp.com>, w3c-rdfcore-wg@w3.org


I don't know... I thought I was just following up an assigned action, and 
didn't go checking for wider context:

williams-01 (revised proposal):
latest amendment reflect comment from Patrick

  williams-01 is rejected, but the text is made more consistent as in msg 0199
ACTION jjc update CONCEPTS in light of decision williams 01
ACTION gk respond wrt williams 01
-- http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Apr/0207.html
    (agendum 16)


At 11:54 09/05/2003 +0100, Brian McBride wrote:
>At 14:10 11/04/2003 +0100, Graham Klyne wrote:
>>With reference to:
>>   http://www.w3.org/2001/sw/RDFCore/20030123-issues/#williams-01
>Which is closed an accepted:
>   http://www.w3.org/2001/sw/RDFCore/20030123-issues/#williams-01
>did I mess up somewhere?
>>I propose that this comment is addressed by revised text at:
>>(copied below)
>>This revision is to bring the introduction of the RDF graph concept, and 
>>its use of URIs, into line with the agreed model [1], as articulated by 
>>Pat [2].  The text has been revised from my original proposal in response 
>>to discussion on the RDFcore list.  The change in terminology (property 
>>-> predicate) means that the GIF image used section 3.1 is revised.
>>[1] [[[ref?]]]
>>[2] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2003Feb/0152.html
>>I also note that the description of abstract graph syntax in section 6 is 
>>already consistent with this model.
>>3.1 Graph data model
>>The underlying structure of any expression in RDF is a collection of 
>>triples, each consisting of a subject, a predicate and an object. A set 
>>of such triples is called an RDF graph (defined more formally in section 
>>6). This can be illustrated by a node and directed-arc diagram, in which 
>>each triple is represented as a node-arc-node link (hence the term "graph").
>>   [image of the RDF triple comprising (subject, predicate, object)]
>>Each triple represents a statement of a relationship between the things 
>>denoted by the nodes that it links. Each triple has three parts:
>>    1. a subject,
>>    2. an object, and
>>    3. a predicate (also called a property) that denotes a relationship.
>>The direction of the arc is significant: it always points toward the object.
>>The nodes of an RDF graph are its subjects and objects.
>>The assertion of an RDF triple says that some relationship, indicated by 
>>the predicate, holds between the things denoted by subject and object of 
>>the triple.  The assertion of an RDF graph amounts to asserting all the 
>>triples in it, so the meaning of an RDF graph is the conjunction (logical 
>>AND) of the statements corresponding to all the triples it contains.  A 
>>formal account of the meaning of RDF graphs is given in [RDF-SEMANTICS].
>>3.2 URI-based vocabulary
>>A node may be a URI with optional fragment identifier (URI reference, or 
>>URIref), a literal, or blank (having no separate form of 
>>identification).  Properties are URI references. (See [URI], section 4, 
>>for a description of URI reference forms, noting that relative URIs are 
>>not used in an RDF graph. See also section 6.4.)
>>A URI reference or literal used as a node identifies what that node 
>>represents.  A URI reference used as a predicate identifies the 
>>relationship between the nodes it connects.  A predicate URI reference 
>>may also be a node in the graph.
>>A blank node is a node that is not a URI reference or a literal.  In the 
>>RDF abstract syntax, a blank node is just a unique node that can be used 
>>in one or more RDF statements, and has no globally distinguishing identity.
>>A convention used by some linear representations of an RDF graph to allow 
>>several statements to reference the same unidentified resource is to use 
>>a blank node identifier, which is a local identifier that can be 
>>distinguished from all URIs and literals. When graphs are merged, their 
>>blank nodes must be kept distinct if meaning is to be preserved; this may 
>>call for re-allocation of blank node identifiers. Note that such blank 
>>node identifiers are not part of the RDF abstract syntax, and the 
>>representation of triples containing blank nodes is entirely dependent on 
>>the particular concrete syntax used.
>>Graham Klyne
>>PGP: 0FAA 69FF C083 000B A2E9  A131 01B9 1C7A DBCA CB5E
>Graham Klyne
>PGP: 0FAA 69FF C083 000B A2E9  A131 01B9 1C7A DBCA CB5E
Received on Friday, 9 May 2003 15:10:55 UTC

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