Re: on divergence between textual and SPARQL definitions

Peter,

On 09/12/16 02:46, Peter F. Patel-Schneider wrote:
...
> The SPARQL definition here uses the following SPARQL query
>
> SELECT DISTINCT $this ?value
> WHERE {
>   $this ex:p ?value .
>   FILTER NOT EXISTS
>     { $value rdf:type/rdfs:subClassOf* $class . }
>   }
>
> with this pre-bound to ex:n and class pre-bound to ex:c.
>
> According to the SHACL document
> evaluating this SPARQL query will produce a non-empty solution sequence,
> namely
>   { { (this, ex:m), (value,ex:l) } }
> because
>   $this ex:p ?value .
> will produce the set of solutions
>   { { (this, ex:n), (value,ex:m) } ,
>     { (this, ex:m), (value,ex:l) } }

I don't follow this part.

On just the " $this ex:p ?value ." pattern, why, when ?this=ex:n, is the 
second solution present?

I think there is only one match. { { (this, ex:n), (value,ex:m) } }
and then the overall result is zero rows.


For both proposal-A and proposal-B used for pre-binding, that seems to 
be the case.  $this is restricted before the FILTER is applied.

(NB I acknowledge that Proposal-A is not proposed for pre-binding and 
wasn't suggested as such)

 Andy

Received on Friday, 9 December 2016 10:20:17 UTC