On 7 Mar 2006, at 17:12, Peter F. Patel-Schneider wrote: >> Ah. Well, for (this version of) SPARQL the scoping set contains >> exactly the >> URIs, the Literals, and the bnodes from the scoping graph. It is a >> theorem that > > I don't see any such theorem in the documents. > >> under these restrictions the definitions given in 2.5 uniquely >> identify the answer >> set - modulo renaming of bnodes - such that the answer set is >> exactly the >> outcome of the homomorphisms between the query and the scoping graph. From section 2.5.2: "A pattern solution can then be defined as follows: to match a basic graph pattern under simple entailment, it is possible to proceed by finding a mapping from blank nodes and variables in the basic graph pattern to terms in the graph being matched; a pattern solution is then a mapping restricted to just the variables, possibly with blank nodes renamed. Moreover, a uniqueness property guarantees the interoperability between SPARQL systems: given a graph and a basic graph pattern, the set of all the pattern solutions is unique up to blank node renaming." cheers --e.
Received on Tuesday, 7 March 2006 18:35:56 UTC