- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Thu, 19 May 2005 12:34:50 +0100
- To: Dan Connolly <connolly@w3.org>
- CC: www-archive@w3.org, Pat Hayes <phayes@ihmc.us>, "Eric Prud'hommeaux" <eric@w3.org>
Andy wrote ">" and ">>>" Dan wrote ">>" <snip/> >>>A substitution is a function from a subset of the set of variables to >>>the set of RDF terms, RDF-T. >>> >>>The result of replacing every v in a graph pattern P by S(v) is >>>written S(P). >>> >>>We say that S is a solution of P if P matches G with substitution S. >>> >>>Definition: Basic Graph Pattern >>> >>>A Basic Graph Pattern is a set of Triple Patterns. >>> >>>A basic graph pattern matches on graph G with substitution S if S(GP) >>>is entailed by G. >>> >>>Definition: Query Solution >>> >>>A Query Solution is a Pattern Solution for the Query Pattern. A >>>substitution in a query solution only contains variables mentioned in >>>the query. >>> >> >>suggest: >> >>Given a Query Pattern, a Query Solution is one of its Pattern Solutions >>whose substitutions only contains variables mentioned in the Query >>Pattern. > > > I don't see the need for a restriction to only contain variables mentioned in > the query. Is there a technical reason for this? > > Allowing other variables/values in a solution does no harm as far as I can see > and allows for later extension to nested queries. > > I have to change the Query Results from saying plain "all" because of variable > inference capabilities. I will add to the definition of basic pattern that every variable mentioned in the baisc pattern must be mentioned in the solution to the basic pattern. This, I think, falls out naturally by "entails" so it will be in the text, not teh definition. Andy
Received on Thursday, 19 May 2005 11:37:01 UTC