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The bloody theoreticians got rid of the OrderedMerge

From: Enrico Franconi <franconi@inf.unibz.it>
Date: Tue, 24 Jan 2006 17:45:45 +0100
Message-Id: <992AE607-17D4-44AF-BF5C-31E3E56C857F@inf.unibz.it>
Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
To: Andy Seaborne <andy.seaborne@hp.com>

[we have done our homework to make the crowd happy]

To Andy:

We have a satisfactory set of definitions that do use the union and  
don't use the OrderedMerge.

Pat's proposal was unsatisfactory (is not upward compatible), but the  
following is upward compatible, and it is just a minor (but crucial!)  
rewording wrt Pat's proposal.

This requires only a minimal rewording wrt rq23 1.613 as follows:

a) Delete the definition of OrderedMerge :-)

b) This is the new definition for basic graph pattern matching:

Definition:  Basic Graph Pattern
A Basic Graph Pattern is a set of Triple Patterns.
Given an entailment regime E, a basic graph pattern BGP, and RDF  
graph G, with scoping graph G', then BGP E-matches with pattern  
solution S on graph G with respect to scoping set B if:
     * (G' Union S(BGP')) is a well-formed RDF graph for E-entailment
     * G E-entails (G' Union S(BGP'))
     * The identifiers introduced by S all occur in B
     * BGP' is an RDF Graph that is graph-equivalent to BGP
     * G' and BGP' do not share any bnode name

c) Delete:
"If the scoping graph G' is such that it does not share blank nodes  
with basic graph pattern, then the above definition can be simplified  
to use a graph union instead of an ordered merge."

d) Delete all the @@**

e) the rest remains the same as in rq23 1.613

Now we have exactly what Pat is asking for, and FUB is happy as well.

--e.
Received on Tuesday, 24 January 2006 16:46:00 GMT

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