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Re: Using rdf reification to nest statements in N3 like contexts

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Fri, 15 Mar 2002 07:10:33 +0000
Message-Id: <5.1.0.14.0.20020315070923.030c89b8@0-mail-1.hpl.hp.com>
To: Graham Klyne <GK@NineByNine.org>, "Seth Russell" <seth@robustai.net>
Cc: "www-rdf-comments" <www-rdf-comments@w3.org>
rdf-comments is for formal communication with the WG.  This thread seems to 
be more of a general discussion.  Please consider moving it to rdf-interest 
or rdf-logic.

Brian


At 23:43 14/03/2002 +0000, Graham Klyne wrote:
>Seth,
>
>With the first level of nesting, I agree that the number of triples for N 
>statements increases to 4N.
>
>But with the next level of nesting, in the framework I was describing, 
>each of those 4N triples itself becomes 4-fold, for a total, of 16N.  Next 
>level of nesting gives 64N.  etc.
>
>Sure, there's a lot of redundant information in there, which is my point 
>about implementations optimizing the representation.  What I'm trying to 
>say here is that the reification quad gives us a way to formally represent 
>this kind of information, but that a pragmatic encoding with 1:1 
>correspondence can be more efficient.
>
>E.g., consider:
>
>(1)  s p o .
>
>(2)  _:s1 rdf:type rdf:Statement .
>      _:s1 rdf:subject s .
>      _:s1 rdf:property p .
>      _:s1 rdf:object o .
>
>(3)  _:s21 rdf:type rdf:Statement .
>      _:s21 rdf:subject _:s1 .
>      _:s21 rdf:property rdf:type .
>      _:s21 rdf:object rdf:statement .
>
>      _:s22 rdf:type rdf:Statement .
>      _:s22 rdf:subject _:s1 .
>      _:s22 rdf:property rdf:subject .
>      _:s22 rdf:object s .
>
>      _:s23 rdf:type rdf:Statement .
>      _:s23 rdf:subject _:s1 .
>      _:s23 rdf:property rdf:property .
>      _:s23 rdf:object p .
>
>      _:s24 rdf:type rdf:Statement .
>      _:s24 rdf:subject _:s1 .
>      _:s24 rdf:property rdf:object .
>      _:s24 rdf:object o .
>
>(4)  ...etc...
>
>#g
>--
>
>At 01:13 PM 3/14/02 -0800, Seth Russell wrote:
>>From: "Graham Klyne" <GK@ninebynine.org>
>>
>> > That said, I rather like this idea.  As it happens, I've made some
>> > notes about extending the model theory to handle N3 style contexts
>> > (which I think map quite nicely to this suggestion):
>> >
>> >    http://www.ninebynine.org/RDFNotes/UsingContextsWithRDF.html
>>
>>Which is much appreciated :)   But in which you say:
>>[[
>>Using this approach, the number of triples will increase exponentially with
>>the depth of context nesting.
>>]]
>>
>>Which I don't think is true.  I think it is basically just 4 (maybe 5) times
>>the number of triples. The number of triples for any level of nesting is
>>just 4N + (if N>1, N)  where N is the number of statements in whatever level
>>of nesting past the top.  Note this even provides that all the statements in
>>one context are conjunctive.  See mentograph:
>>
>>http://robustai.net/mentography/nesting_context.gif
>>
>>Seth Russell
>
>-------------------
>Graham Klyne
><GK@NineByNine.org>
Received on Friday, 15 March 2002 02:23:41 GMT

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