Re: rq23 def'n "Pattern Solution" wrong? (and more on BGP')

On 5 Mar 2006, at 20:26, Pat Hayes wrote:
> Imposing disjointness between bnode sets is however a real  
> syntactic constraint, one that is reflected in detectable  
> properties of a surface syntax: in our case, it means that SPARQL  
> does not support an answer semantics which would require bnodes to  
> be shared between query patterns and answer bindings. And indeed,  
> it does not. So, we should phrase the definitions to reflect this  
> fact.

Again and again, this is the whole point:

- according to your restricted semantics, answer sets are allowed to  
use arbitrary bnodes, including the ones in the dataset, but not the  
ones in the query.

According to you, SPARQL should support an answer semantics where  
bnodes can be shared between data sets and answer bindings, but  
SPARQL should *not* support an answer semantics where bnodes can be  
shared between query patterns and answer bindings.

Why? It seems arbitrary to me.

--e.