- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Mon, 13 Jun 2005 14:47:43 +0100
- To: Jeen Broekstra <jeen@aduna.biz>
- CC: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Jeen Broekstra wrote: > SPARQL language editor's draft rev 1.379 > http://www.w3.org/2001/sw/DataAccess/rq23/ > > In section 2.4 the terms 'Pattern Solution', 'Query Solution' and > 'Basic Graph Pattern' are defined, > > The definition of Basic Graph Pattern includes what it means to match > against a graph. It would be better to create a separate definition > for this, called 'Graph Pattern Match'. The definition of 'Basic Graph > Pattern' can then be moved to the start of the section, and in any > case I think an explicit definition of pattern match, that links graph > patterns to solutions, is a lot clearer. > > Also, the current definition of a match is imprecise. It uses the > notion 'entails' without specifying what that means. Is that simple > entailment, RDF(S) entailment, or an entirely different, more loose > form of entailment? I request instead using the notion of 'subgraph' > for defining a match. It has already gone back to being "subgraph" to avoid entailment. Simple entailment does not add anything (except a lot of blank nodes). "Entailment" does not define what kind. The match can be a subgraph of an entailed graph, putting the entailment outside the SPARQL doc. > > Suggested definitions: > > Definition: *Basic Graph Pattern* > > A /basic graph pattern/ is a set of Triple Patterns. > > Definition: *Graph Pattern Match* > > A graph pattern /matches/ on a graph G with pattern solution S iff > S(GP) is a non-empty subgraph of G. This is at odds with later definitions. This defn is only basic patterns. I have left order as is but 2.4 is split: 2.4 Pattern Solutions 2.5 Basic Graph Patterns and old 2.5 (example) is part of new 2.5 as well. > > Jeen v1.391 Andy
Received on Monday, 13 June 2005 13:51:27 UTC