W3C home > Mailing lists > Public > public-sparql-dev@w3.org > April to June 2016

Re: can subqueries be executed first in SPARQL? (previous example messed up)

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Mon, 27 Jun 2016 08:52:49 -0700
To: james anderson <james@dydra.com>, public-sparql-dev@w3.org
Message-ID: <2b568d0a-322d-3d2b-e00b-65687f393353@gmail.com>
Oops, in my attempt to show what was happening with a disconnected variable, I
messed up completely.  My apologies.  A corrected version will be available
shortly.

peter


On 06/27/2016 08:28 AM, james anderson wrote:
> 
>> On 2016-06-27, at 16:05, Peter F. Patel-Schneider <pfpschneider@gmail.com
>> <mailto:pfpschneider@gmail.com>> wrote:
>>
>> […]
>>
>> Project(
>>  { (x,:b) |
>>    eval( D(G),
>>      substitute(
>>        Join(
>>          Extend( Z, y, :c ) ,
>>          ToMultiset( Project( ToList( BGP(?z :d ?x) ) , z ) )
>>          )
>>        (x,:b) )
>>      ) /= { } } ,
>>  x
>>  )
>>
>> Project(
>>  { (x,:b) |
>>    eval( D(G),
>>        Join(
>>          Extend( Z, y, :c ) ,
>>          ToMultiset( Project( ToList( BGP(?z :d :b) ) , z ) )
>>          )
>>      ) /= { } } ,
>>  x
>>  )
> 
> if i follow this, this reduction obtains iff the project has no effect on the
> scope the binding for ?x which was established by the outer extend.
> is that intended?
> 
> best regards, from berlin,
> 
> 
> ---
> james anderson | james@dydra.com <mailto:james@dydra.com> | http://dydra.com
> 
> 
> 
> 
> 
Received on Monday, 27 June 2016 15:53:28 UTC

This archive was generated by hypermail 2.3.1 : Monday, 27 June 2016 15:53:29 UTC