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Re: First order logic and SPARQL

From: Adrian Walker <adriandwalker@gmail.com>
Date: Mon, 6 Sep 2010 08:02:30 -0500
Message-ID: <AANLkTikCm6o_0nLubF9FsiVmctQAgibVefLhANXGCFrZ@mail.gmail.com>
To: Bob MacGregor <bob.macgregor@gmail.com>
Cc: semantic-web@w3.org, public-sparql-dev@w3.org
Hi Bob --

For a proposal for a query language for RDF that's easy to use, please see

   www.reengineeringllc.com/demo_agents/RDFQueryLangComparison1.agent

(You can view *run *and change the example by pointing a browser to the same
site.  There are semi-technical user level explanations of answers)

A problem with SPARQL as a target language for a compiler is that it lacks a
model theoretic semantics, and that aggregation appears to be highly
implementation dependent.

SQL as a target language suffers some of the same difficulty, but the
problem is more pressing for SPARQL because it is intended to bridge many
endpoints (with possibly different implementations) in a single query.

                                       -- Adrian


Internet Business Logic
A Wiki and SOA Endpoint for Executable Open Vocabulary English Q/A over SQL
and RDF
Online at www.reengineeringllc.com
Shared use is free, and there are no advertisements

Adrian Walker
Reengineering


On Sun, Sep 5, 2010 at 4:48 PM, Bob MacGregor <bob.macgregor@gmail.com>wrote:

> My personal interest is in a query language for RDF that's easy to use,
> and, among other things,
> has a negation operator that is intuitive.  If SPARQL 1.1 adds a negation
> operator, that is good to know.
>
> I would  be interested to learn of a datalog-with-negation implemented by
> translating to SPARQL,
> since datalog and its variants is IMO intuitive.   Are the results that
> show a mapping between
> a datalog variant and SPARQL just papers, or has someone actually
> implemented a Datalog-like
> front end that translates to SPARQL?  I'd like to see that.  Note: Axel
> cites a paper that translates
> in the other direction -- that's not what I'm after.
>
> - Bob
>
Received on Monday, 6 September 2010 13:02:59 GMT

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