- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Mon, 28 Nov 2016 09:49:54 -0800
- To: Andy Seaborne <aseaborne@topquadrant.com>, public-sparql-exists@w3.org
On 11/28/2016 08:26 AM, Andy Seaborne wrote:
>
>
> On 26/1
>>
> Example 4
>> SELECT ?x WHERE {
>> ?x :p :v .
>> FILTER ( EXISTS {
>> :a :q :c . MINUS { :a :q :c . }
>> } )
>> }
>>
>> Specification { { (x,:s) } }
>
> It's {}
>
> { :a :q :c . MINUS { :a :q :c . } }
>
> is empty because the left-hand BGP does not match.
>
> Maybe you meant:
>
> :s :p :v MINUS { :s :p :v }
>
> or
>
> :s :p :v MINUS { :t :r :v }
Yes, either My (stupid) mistake.
>
>> Proposal A { { (x,:s) } }
> How?
With the change, the both BGPs match and have "compatible" solutions but don't
share variables so the LH matches are not removed.
>
>
>
>> Proposal B { }
> Yes.
With the change, both BGPs share variables so the LH matches are all removed.
>
>> Expected* { { (x,:s) } }
>> * Expected only if the flipping nature of MINUS is considered to be
>> expected, otherwise the expected result would be { }.
>>
>
Received on Monday, 28 November 2016 17:50:28 UTC