- From: Andy Seaborne <andy.seaborne@epimorphics.com>
- Date: Tue, 01 Mar 2011 17:35:18 +0000
- To: nathan@webr3.org
- CC: RDF WG <public-rdf-wg@w3.org>
On 01/03/11 17:23, Nathan wrote: > Andy Seaborne wrote: >> On 01/03/11 16:41, Nathan wrote: >>> actually ^ may be better.. such that >>> >>> :a :b :c . >>> >>> could be written as: >>> >>> :c ^:b :a . >>> >>> meaning >>> >>> :c [ owl:inverseOf :b ] :a . >> >> meaning there is a there is bnode in the predicate position. >> >>> >>> meaning: >>> >>> :a :b :c . >>> >> >> SPARQL has: >> >> :c ^:b :a . >> >> meaning >> >> :a :b :c >> >> reverses subject and object. The matching process really does swap >> subject and object. >> >> http://www.w3.org/TR/sparql11-query/#propertypaths > > wouldn't that require subjects as literals? Yes. http://www.w3.org/TR/rdf-sparql-query/#sparqlTriplePatterns They are legal in SPARQL 1.0; they just never match. In a practical sense, it's unavoidable in explaining: Data: :x :p "abc" . Query pattern: { ?x :p ?o . ?o :q ?z <--- **** } or { ?x :p ?o . OPTIONAL {?o :q ?z } <--- **** } Andy
Received on Tuesday, 1 March 2011 17:35:56 UTC