- From: Andy Seaborne <andy.seaborne@talis.com>
- Date: Thu, 04 Mar 2010 14:53:09 +0000
- To: sparql Working Group <public-rdf-dawg@w3.org>
In http://lists.w3.org/Archives/Public/public-rdf-dawg-comments/2010Feb/0018.html Rob Vesse observes that "no duplicates" is at odds with the expansion of a simple path (a term we have already decided to remove) into a triple pattern because there is an implicit projection going on. {?x foaf:knows{2} ?y} is not quite the same as { ?x foaf:knows ?z . ?z foaf:knows ?y } when there are acylic components/ e.g.: :a foaf:knows :b . :a foaf:knows :c . :b foaf:knows :d . :c foaf:knows :d . because ?z is projected away. We can specify either way: + emphasis that certain property paths are the same as the triple expansion form, and not have the striuct no duplicates rule (this reintroduces the simple property paths concept) or + note, and provide an example, that they are not exactly equivalent. I prefer the latter - keep the "no duplicates" situation. Note this is related to "[TF-PP] cycles - simple or a walk" http://lists.w3.org/Archives/Public/public-rdf-dawg/2010JanMar/0455.html Andy Andy
Received on Thursday, 4 March 2010 14:53:45 UTC