- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Mon, 30 Jan 2006 12:40:26 +0000
- To: Enrico Franconi <franconi@inf.unibz.it>
- CC: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Enrico Franconi wrote: > """ > Definition: Basic Graph Pattern equivalent > Two basic graph patterns are basic graph pattern equivalent if there > is a bijection between the nodes of the triple patterns that maps > blank nodes to blank nodes and maps variables, literals and IRIs to > themselves. > """ > > Mmhhh, I'm not sure it is correct :-( See latest (v1.626) - you're tracking an intermedate version where I had only tidied up a bit, not reflect the more recent discussions. Andy > You need to maintain the structure, not only the nodes (item 5. > below)... > I still believe that either we have the real formal notion, or just > the informal one: > > option a) > """ > Two basic graph patterns BGP and BGP' are graph-equivalent if there > is a bijection M between the sets of nodes of the two basic graph > patterns, such that: > 1. M maps blank nodes to blank nodes. > 2. M(lit)=lit for all RDF literals lit which are nodes of BGP. > 3. M(iri)=iri for all RDF IRI references uri which are nodes of BGP. > 4. M(var)=var for all query variables var which are nodes of BGP. > 5. The triple ( s, p, o ) is in BGP if and only if the triple ( M > (s), M(p), M(o) ) is in BGP'. > """ > > option b) > """ > Two basic graph patterns are graph-equivalent if they are the same up > to bnode renaming. > """ > > > --e.
Received on Monday, 30 January 2006 12:40:31 UTC