W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > April to June 2010

Re: [Entailment] D-entailment (and upwards) issue?

From: Andy Seaborne <andy.seaborne@talis.com>
Date: Tue, 11 May 2010 08:54:54 +0100
Message-ID: <4BE90D4E.6040402@talis.com>
To: Axel Polleres <axel.polleres@deri.org>
CC: SPARQL Working Group <public-rdf-dawg@w3.org>


On 11/05/2010 7:53 AM, Axel Polleres wrote:
> When thinking about what we called "D^-"-entailment at the f2f, I realised the following possible issue for all
> datatype aware entailment regimes (D-entailment, OWL, RIF, ...):
>
> Entailment regimes in general are defined only in terms of BGP matching, but nothing else in the algebra, particularly FILTER evaluation
> is independent from the entailment regime. FILTER evaluation is specified solely in the query document at this point.
>
> However, I am afraid this might lead to unexpected behaviors... take the following example:
>
> G:  :s :p "1"^^xs:integer
>
> Query1:
>
>   SELECT * WHERE {?S ?P "1.00"^^xs:decimal }
>
> Query2:
>
>   SELECT * WHERE {?S ?P ?O FILTER(?O = "1.00"^^xs:decimal) }
>
>
> Since constants in FILTERs are not affected by canonicalisation, D-Entailment, would only give an answer to Query1, right?

Query 2 will return at least one row for any entailment regime, 
including simple.

"=" in FILTERs is a value-based comparison. (c.f. sameTerm)  Here, it 
dispatches to op:numeric-equals.

http://www.w3.org/TR/xpath-functions/#func-numeric-equal

	Andy
Received on Tuesday, 11 May 2010 07:55:30 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:42 GMT