13:55:44 RRSAgent has joined #sparql 13:55:44 logging to http://www.w3.org/2009/05/19-sparql-irc 13:56:04 SimonS has joined #sparql 13:56:11 Zakim has joined #sparql 13:56:19 Zakim, this is SPARQL 13:56:19 AxelPolleres, I see SW_(SPARQL)10:00AM in the schedule but not yet started. Perhaps you mean "this will be SPARQL". 13:56:26 Zakim, this will be SPARQL 13:56:26 ok, AxelPolleres; I see SW_(SPARQL)10:00AM scheduled to start in 4 minutes 13:57:00 pgearon has joined #sparql 13:57:04 trackbot, start meeting 13:57:06 RRSAgent, make logs world 13:57:08 Zakim, this will be 77277 13:57:08 ok, trackbot; I see SW_(SPARQL)10:00AM scheduled to start in 3 minutes 13:57:09 Meeting: SPARQL Working Group Teleconference 13:57:09 Date: 19 May 2009 13:57:44 SW_(SPARQL)10:00AM has now started 13:57:46 LukeWM has joined #sparql 13:57:51 + +1.216.445.aaaa 13:58:00 Zakim, aaaa is me 13:58:00 +john-l; got it 13:58:22 + +3539149aabb 13:58:25 -john-l 13:58:26 +john-l 13:58:34 +??P20 13:58:37 zakim, ??P20 is me 13:58:37 +AndyS; got it 13:58:40 +[IPcaller] 13:58:54 + +0005aacc 13:58:56 + +1.312.863.aadd 13:58:57 +??P18 13:59:08 Zakim: ??P18 is me 13:59:09 Zakim, who is speaking? 13:59:14 Zakim, ??P18 is me 13:59:14 +KjetilK; got it 13:59:14 Zakim, IPcaller is me 13:59:15 +kasei; got it 13:59:20 +??P26 13:59:21 AxelPolleres, listening for 10 seconds I could not identify any sounds 13:59:25 Zakim, mute me 13:59:25 KjetilK should now be muted 13:59:26 zakim, ??p26 is me 13:59:26 +bijan; got it 13:59:28 Zakim, aacc is me 13:59:29 +SimonS; got it 13:59:37 SteveH has joined #sparql 13:59:38 Zakim, who is on the phone? 13:59:41 On the phone I see john-l, AxelPolleres, AndyS, kasei, +1.312.863.aadd, SimonS, KjetilK (muted), bijan 14:00:04 Zakim, mute me 14:00:04 AxelPolleres should now be muted 14:00:11 Zakim, mute me 14:00:22 kasei should now be muted 14:00:29 Zakim, mute aadd 14:00:44 +1.312.863.aadd should now be muted 14:00:55 +??P28 14:01:13 P28 might be me, not sure 14:01:16 +??P29 14:01:17 +Lee_Feigenbaum 14:01:18 there was a big delay 14:01:29 zakim, who's on the phone? 14:01:29 On the phone I see john-l, AxelPolleres (muted), AndyS, kasei (muted), +1.312.863.aadd (muted), SimonS, KjetilK (muted), bijan, ??P28, ??P29, Lee_Feigenbaum 14:01:30 Zakim: ??P28 is me 14:01:34 Zakim, ??P28 is me 14:01:34 +AlexPassant; got it 14:01:44 I'll dial out and back so I get the number... 14:01:49 -AlexPassant 14:01:59 oh, so I'm not P28 :) 14:02:14 Zakim, ??P29 is me 14:02:14 +AlexPassant; got it 14:02:22 +??P28 14:02:31 Zakim, ??P28 is [Garlik] 14:02:31 +[Garlik]; got it 14:02:40 Zakim, [Garlik] has SteveH, LukeWM 14:02:40 +SteveH, LukeWM; got it 14:02:55 zakim, unmute aadd 14:02:56 +1.312.863.aadd should no longer be muted 14:03:14 Zakim, unmute me 14:03:14 AxelPolleres should no longer be muted 14:03:32 looking it up 14:03:45 + +1.937.775.aaee 14:03:55 up: #41. hand down: #40 14:03:55 41# 14:04:08 http://www.w3.org/2002/01/UsingZakim 14:04:24 zakim, aadd is pgearon 14:04:24 +pgearon; got it 14:04:26 q- 14:04:32 +EricP 14:04:50 zakim, 937 is prateek 14:04:50 sorry, LeeF, I do not recognize a party named '937' 14:04:58 zakim, aaee is prateek 14:04:58 +prateek; got it 14:05:02 zakim, who's on the phone? 14:05:02 On the phone I see john-l, AxelPolleres, AndyS, kasei (muted), pgearon, SimonS, KjetilK (muted), bijan, AlexPassant, Lee_Feigenbaum, [Garlik], prateek, EricP 14:05:06 [Garlik] has SteveH, LukeWM 14:05:39 Prateek has joined #sparql 14:05:47 scribenick: bijan 14:06:35 topic: admin 14:06:42 PROPOSED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-04-28 14:07:03 +1 14:07:13 RESOLVED: Approve minutes at http://www.w3.org/2009/sparql/meeting/2009-04-28 14:07:13 bijan has changed the topic to: http://www.w3.org/2009/sparql/wiki/Agenda-2009-05-19 14:07:37 AndyS: Pity that the new minutes don't group axioms 14:07:44 LeeF: Pester Sanrdo. 14:07:56 s/axioms/actions/ 14:08:18 LeeF: Meeting next week, same bat time, same bat channel, chime as scribe 14:08:25 Topic: Liasons 14:08:34 LeeF: Anything we need to know? 14:08:36 Crickets. 14:08:48 q+ on rdf-text 14:08:51 ericP: Lots of hot rdf:text action 14:08:51 q+ to ask about Social Web XG liaison 14:08:54 q- aadd 14:09:02 q- +1.312.863.aadd 14:09:42 ...What I can gather is that people are ok with inferred rdf:text being invisible to sparql query. But AndyS gave 3 proposals and I was in favor of 1. AndyS could you list them? 14:09:43 q-i AxelPolleres 14:09:52 AndyS: Now? Is it agenda sane? 14:10:13 AxelPolleres: We are due to set up a telecon with all the related parties on it. Soon. 14:10:34 LeeF: Let's defer to the looped people until we have a proposed resolution. 14:10:46 ...Any non-looped callers want to talk about it? 14:10:50 14:10:55 not sure if I'm in the loop or not... I was 14:10:59 ack AlexPassant 14:10:59 AlexPassant, you wanted to ask about Social Web XG liaison 14:11:21 AlexPassant: There's a new XG on Social Web and I'd like to be the liaison for that 14:11:28 LeeF: Superfantastic! 14:11:30 -> http://lists.w3.org/Archives/Public/public-rdf-text/2009AprJun/0083.html 14:11:45 Topic: F2F1 recap 14:11:52 http://www.w3.org/2005/Incubator/socialweb/ 14:11:52 -> http://www.w3.org/2009/sparql/meeting/2009-05-06 14:11:56 -> http://www.w3.org/2009/sparql/meeting/2009-05-07 14:12:18 -> http://www.w3.org/2009/sparql/wiki/FeatureProposal 14:12:20 LeeF: The minutes are about ready, see links. 14:13:09 ...we've decided to work on some things and we decided on a naming scheme, i.e., SPARQL/*, e.g., SPARQL/Query SPARQL/Update 14:13:38 ...Sublanguages are independently versions, thus DAWG SPARQL/Query is 1.0 and our SPARQL/Query is 1.1 14:13:50 ...Something about subselect or something 14:14:20 ...Following AndyS's suggestion we'll have a wiki design template for all sorts of spec development. 14:14:22 ...Questions? 14:14:37 http://www.w3.org/2009/sparql/wiki/Template:DesignQL 14:15:01 Example: 14:15:02 http://www.w3.org/2009/sparql/wiki/Design:SubSelect 14:15:09 LeeF: Let's go over status of Actions both to close ones that are read and to shame people who are slackin' 14:15:34 :( I'm late with sub-SELECT samples :( 14:15:59 ...Right now the tracker is set up so anyone can close actions (not axioms). But the chairs would prefer that people would not *close* actions when done but set them to "pending review" so the chairs have an easier time with bookkeeping. 14:16:13 http://www.w3.org/2009/sparql/track/actions/open 14:16:19 http://www.w3.org/2009/sparql/track/actions/pendingreview 14:17:08 q+ to say about action UI 14:17:14 LeeF: Also, Bijan explained that tracker will track email about an action or issue if you include anywhere in an email (ISSUE|ACTION):d+ where :d+ is the relevant action/issue number 14:17:23 ...so please do this! 14:17:24 ack SteveH 14:17:24 SteveH, you wanted to say about action UI 14:17:43 http://www.w3.org/2009/sparql/track/actions/13 14:17:47 SteveH: It also picks up uris of the action/issue 14:18:07 LeeF: Cool. 14:18:12 q+ to pimp it 14:18:20 ack bijan 14:18:20 bijan, you wanted to pimp it 14:18:31 bijan: OWL experience is that this is super duper useful 14:18:42 -EricP 14:19:01 Topic: Pending review actions 14:19:26 +EricP 14:19:36 LeeF: ACTION-14 (bijan). It's done. 14:19:43 trackbot, close ACTION-14 14:19:43 ACTION-14 Send mail about issues in specifying OWL in SPARQL semantics closed 14:20:26 LeeF: ACTION-18 (Axel). We'll talk about this later in the call. It's good. 14:20:39 trackbot, close ACTION-18 14:20:39 ACTION-18 Write up a use case on !ASK in FILTERS to emulate negation closed 14:21:13 trackbot, close ACTION-20 14:21:13 ACTION-20 Send CONSTRUCT in FROM clause use case to mailing list re: ISSUE-7 closed 14:21:43 trackbot, close ACTION-24 14:21:43 ACTION-24 Explain potential design regarding aggregate functions with multiple answers for mixed datatypes re ISSUE-16 closed 14:22:22 trackbot, close ACTION-25 14:22:22 ACTION-25 Setup wiki template and feature stub pages based on slide 11 of http://jena.hpl.hp.com/~afs/SPARQL-F2F1-AFS.pdf closed 14:22:24 trackbot, close ACTION-26 14:22:24 ACTION-26 Stub out an initial example of a filled in feature template pending completion of ACTION-25 closed 14:23:02 trackbot, close ACTION-27 14:23:02 ACTION-27 Ask in DERI about whether RDF Forms/pushback uses WHERE in updates closed 14:23:21 trackbot, close ACTION-30 14:23:21 ACTION-30 Provide 3 uses cases on wiki closed 14:23:53 trackbot, close ACTION-13 14:23:53 ACTION-13 Write up how/whether assignment is subsumed by projected expressions + subqueries (tentative, with LukeWM) closed 14:24:13 trackbot, close ACTION-29 14:24:13 ACTION-29 Provide FOAF update use case on wiki closed 14:25:29 Topic: Review Template:DesignQL 14:25:32 http://www.w3.org/2009/sparql/wiki/Template:DesignQL 14:26:16 LeeF: We can use this to put competing designs and even language side by side. AndyS? 14:27:13 AndyS: This is a bit tuned for the query language. Design early and often for concrete direction. <> 14:28:03 "design early - design often" 14:28:33 LeeF: And people should feel free to add bits to arbitrary sections. 14:28:54 -> http://www.w3.org/2009/sparql/wiki/Design:SubSelect 14:29:11 LeeF: Check out AndyS's first example for SubSelect 14:29:46 Topic: F&R document update? 14:30:04 http://www.w3.org/2009/sparql/docs/features/ 14:30:30 LeeF: Who's the audience? Potential implementors? WG wannabees? Users? AC reps? 14:30:50 ...My answer is that this should target implementors and WG wannabees. 14:31:25 +1 to keeping syntax up-to-date -- it caused people some confusion last time when we left old syntax around. 14:31:34 ...I think we should maintain the syntax in the document because these documents are like diamonds...forever. So we can avoid people who stumble on the F&R won't be confused. 14:31:35 +1 14:31:48 I suspect the F&R should avoid syntax whereever possible 14:31:59 ...However, I don't intend the N&F isn't a primer. So, concise, technical document. 14:32:05 +1 for updating syntax when the WG agrees on it 14:32:12 Zakim, unmute me 14:32:15 q+ 14:32:16 KjetilK should no longer be muted 14:32:51 kjetil: My primary concern is how it'll be seen by people outside the SPARQL community. Current stuff is a bit terse. 14:33:19 LeeF: I sorta agree. I don't know what sort of review to expect. I think it's ok to presume familiarity with SPARQL 14:33:22 q+ 14:33:26 ack SteveH 14:34:00 SteveH: I think we should avoid putting in speculative syntax whenever possible. Showing what can't be done is ok, but people *will* implement any scrap of anything no matter what the disclaimers. 14:34:13 LeeF: What about linking out to existing implementations. 14:34:27 SteveH: That should be ok. But w3.org makes people crazy. 14:34:31 ack bijan 14:34:38 q+ 14:34:56 bijan: recommend narrow scope, don't worry about general audience (which would cause a lot of extra work) 14:35:02 +1 to not worrying about general audience, meant to say that too 14:35:11 ack KjetilK 14:35:27 KJetikK: I'm worried that people will come and say it's not well motivated. 14:35:31 I don't think it's a worry. 14:35:59 LeeF: I'm not too worried about it. I expect most feedback from the implementors community. 14:36:19 Also, if someone does have a question, we can deal with it as it arises. 14:36:30 Zakim, mute me 14:36:30 KjetilK should now be muted 14:36:37 Topic: Feature overview: Feature:Negation 14:36:49 http://www.w3.org/2009/sparql/wiki/Feature:Negation 14:36:49 -> http://www.w3.org/2009/sparql/wiki/Feature:Negation 14:37:26 LeeF: So, let's follow the F2F pattern. First get a sense of existing implementions. Fine design issues and start workign on it. 14:37:59 ...Start with overview. Take it to email. Move things back to telecon on a "obvious need" basis. 14:38:54 ...Kicking off negation discussion. You can do just about all the use cases in S/Q 1.0 using optional and notbound. Which is so ugly I'd rather watch videos of parasitic wasps emerging from their catapiller hosts. 14:39:18 ...There are several design out there, but I'd like to know what people do now. 14:39:35 zakim, who's here? 14:39:35 On the phone I see john-l, AxelPolleres, AndyS, kasei (muted), pgearon, SimonS, KjetilK (muted), bijan, AlexPassant, Lee_Feigenbaum, [Garlik], prateek, EricP 14:39:37 ...AndyS, do you have an implementation of simpler negation? 14:39:39 [Garlik] has SteveH, LukeWM 14:39:40 On IRC I see Prateek, SteveH, LukeWM, pgearon, Zakim, SimonS, RRSAgent, AxelPolleres, john-l, bijan, AndyS, karl, AndyS_, LeeF, trackbot, iv_an_ru, kasei, kjetil, AlexPassant, 14:39:43 ... KjetilK, ericP 14:39:48 Zakim, unmute me 14:39:48 kasei should no longer be muted 14:39:53 AndyS: Nothing in release version. Most of my thoughts go back to UNSAID in DAWG. 14:40:07 i implemented UNSAID in Algae2 14:40:09 it worked 14:40:12 . 14:40:38 kasei: We do UNSAID. 14:40:52 pgearon: we have a minus operator. 14:40:53 no negation in ARC2/SPARQL+ 14:40:58 LeeF: Is that like UNSAID? 14:41:06 pgearon: sorta 14:41:12 q+ to ask about MINUS 14:41:26 Sesame/SeRQL has MINUS 14:41:40 ack AndyS 14:41:40 AndyS, you wanted to ask about MINUS 14:41:41 SimonS: Sesame/SeRQL has MINUS 14:42:03 AndyS: Is your minus a set based (each side has to have the same shape) or not? 14:42:22 pgearon: It's set based. It's sorta like an inner join. I have a posting that describes that it detail. 14:42:30 AndyS: Please send the pointer? 14:42:37 pgearon: I'm looking for it. 14:42:59 bijan: None of the owl ones do, to my knowledge. 14:43:08 q+ to summarize MINUS in SeRQL 14:43:16 LeeF: because I'm a sadist, glitter forces you to do it the waspy way 14:43:22 SteveH: We don't do it. 14:43:46 Prateek: We don't have it. 14:43:56 iv_an_ru, what does Virtuoso do for negation? 14:43:59 LeeF: Anyone know what Virtuoso? 14:44:05 AndyS: The might have exists? 14:44:09 I wrote about my description of MINUS in a blog post 2004-10-05: http://gearon.blogspot.com/2004/10/owlsameas-majority-of-today-was-spent.html 14:44:11 we had some very prototypical implementation of ASK in FILTERs ind dlvhex (LP engine based SPARQL implementation)... not released. 14:44:20 (skip the first section on owl:sameAs) 14:44:21 we have subqueries and ! operator, that's enough 14:44:28 http://www.openrdf.org/doc/sesame2/users/ch09.html#d0e2194 14:44:37 We don't have MINUS or UNSAID 14:44:50 SimonS: I checked the docs and found that minus is set based in Seqrl and exists which is Not...something 14:44:54 We've never seen requests for them 14:45:18 SimonS: Minus is an operator that takes two queries and from the results of the first query remove the elements of the second query. 14:45:31 s/...something/ ASK/ 14:45:41 ...EXISTS is NOT ASK filter 14:46:00 sounds like the two sets must bind the same variables, is that right? 14:46:12 LeeF: I presume a good deal of discussion will revolve around which sort, but we're going to defer. 14:46:24 ...From what we've just heard and discussion on the list there are three designs: 14:46:40 ...1) Binary operator that acts on subqueries (SERQL Minus) 14:46:55 ...2) Binary operator *in* a graph pattern (e.g., UNSAID) 14:47:40 ...3) Not exists approach (filter based). AndyS pointed out in email that it wouldn't be exactly the semantics of the compositional form. So maybe a different name 14:47:58 LeeF: Does that design space seem right? 14:48:08 pgearon thinks the FILTER based approach is similar to a SQL left-outer-join 14:48:23 LeeF: Silence is UNSAID assent 14:48:34 I don't understand pgearon's point 14:48:57 ...We need to decide between these. 14:49:07 FILTER/EXISTS is very like SQL EXISTS. 14:49:34 AndyS, the similarity is advantage ;) 14:49:37 ISSUE: Should negation be done via a binary operator on subqueries, a binary operator within graph patterns, or a filter+subquery? 14:49:37 Created ISSUE-29 - Should negation be done via a binary operator on subqueries, a binary operator within graph patterns, or a filter+subquery? ; please complete additional details at http://www.w3.org/2009/sparql/track/issues/29/edit . 14:50:18 LeeF: Get we get some voluteers for UNSAID and MINUS to talk designs on the mailing list. 14:50:19 q+ 14:50:23 ericP: Plus contrasts 14:50:29 q- SimonS 14:50:31 q- 14:50:35 q- 14:50:42 bijan: Email or design template 14:50:46 ISSUE-29 relates to ISSUE-5 (how again do I bring trackbot to link that?) 14:50:50 AndyS: at first, email is better. 14:52:06 -kasei 14:52:11 LeeF: I want to make the barrier to entry very low. So if they can put it in the template, great. 14:52:19 AndyS: Email is nice because it's push. 14:52:40 ericP: I'd love to work on UNSAID with SimonS since he has both 14:52:45 ACTION: ericP to work with SimonS on explaining and comparing UNSAID and MINUS 14:52:45 Sorry, couldn't find user - ericP 14:52:52 ACTION: Eric to work with SimonS on explaining and comparing UNSAID and MINUS 14:52:52 Created ACTION-32 - Work with SimonS on explaining and comparing UNSAID and MINUS [on Eric Prud'hommeaux - due 2009-05-26]. 14:53:15 +??P5 14:53:23 Zakim, P5 is me 14:53:23 sorry, kasei, I do not recognize a party named 'P5' 14:53:25 LeeF: pgearon and kasei if you want to chime in, please do in email 14:53:55 Zakim, ??P5 is kasei 14:53:55 +kasei; got it 14:54:06 thanks KjetilK 14:54:18 LeeF: Any other questions or discussions about negation? iv_an_ru said on irc that they've received no request for negation in graph patterns. So contrasting experience? 14:54:31 ericP: When I did it I didn't have subselects, so it was the only obvious way to do it. 14:54:39 LeeF: Do you have a gut feeling now as to preference? 14:55:01 +1 to ericP 14:55:05 my feeling too 14:55:06 ericP: SQL users are used to a subselect and a not. But to me it has a similar feel to an optional so prefer the ingraph thing 14:55:12 +1 to ericP 14:55:17 LeeF: kasei? 14:55:40 kasei: well, i don't have a lot of experience. I threw it it for kicks. I agree with ericP about the design. 14:56:12 LeeF: AndyS? When you had it what did you have? 14:56:16 q+ 14:56:24 q+ to ask about optimisations 14:56:33 AndyS: It was UNSAID. 14:56:39 I have no technical difficulties with MINUS, we have a similar thing in SQL, but I don't know whether it will be popular. 14:56:48 ack AxelPolleres 14:57:06 AxelPolleres: Does anyone have a preference *against* having both? 14:57:40 LeeF: From scuttlebut, there are people who prefer minimality. For me, I'd only have both if there was a clear functional difference. 14:57:55 AxelPolleres: Reversing it, is there use cases not covered by one but by the other 14:57:57 I don't understand the usability of MINUS. We might be only a little bit better than OPTIONAL/!BOUND, but I hope Simon+Eric will show that to be a false worry. 14:58:02 ericP: [[scribe lost it]] 14:58:06 I'm lazy, that's the only reason I have agains MINUS 14:58:45 ack kjetil 14:58:45 AndyS, can you please elaborate? 14:58:47 KjetilK, you wanted to ask about optimisations 14:58:55 UNSAID { } vs. FILTER ( !EXISTS { } ... any of the two more expressive? 14:59:02 ericP: My suspicious that given that object of an UNSAID is a graph pattern you could stick a subselect there which is a scribe tormenting way to say "No". 14:59:12 KjetilK: Does it matter for optimization? 14:59:29 UNSAID { } vs. FILTER ( !EXISTS { } ... any of the two easieer to optimize? 14:59:34 ericP: My guess is that UNSAID is easier to optimize because you can exhaust possibilities more easily 15:00:35 what if the EXISTS is wrapped into a more complext FILTER expression? Is that the same as wrapping the complex filter inside the UNSAID pattern? 15:00:49 AndyS: I think any of the cases can be done with either. FILTER(!EXISTS... makes it easier to combine with other conditions. UNSAID controls the position of the negation. Optimization: it should be easy to spot when FILTER(!exists is the same as an UNSAID 15:01:04 AxelPolleres: Outside of the UNSAID. 15:01:14 Zakim, mute me 15:01:14 KjetilK should now be muted 15:01:27 -AxelPolleres 15:01:33 {P} FILTER(!EXISTS{Q}) looks to me exactly the binary {P} UNSAID {Q} (he said boldly) 15:01:33 q? 15:01:45 LeeF: Doesn't seem like a huge design space so we should be able to check each out and make progess. 15:01:53 i.e. add {} to the lefty of filter form to foce order. 15:01:55 AndyS, how sure of that are you? 15:02:15 Very .. er .. reasonably 15:02:17 LeeF: Adjourned! 15:02:19 ah, yeah, with the extra {}s 15:02:25 -john-l 15:02:25 -bijan 15:02:28 Let's use the phone in a memo 15:02:29 that's a bit of a special case though 15:02:34 Let's use the phone in a mement. 15:03:28 Yes - adding the {} controls the filter placement. It's a trick/idiom. 15:03:46 -EricP 15:04:02 Zakim, who is on the phone? 15:04:02 On the phone I see AndyS, pgearon, SimonS, KjetilK (muted), AlexPassant, Lee_Feigenbaum, [Garlik], prateek, kasei 15:04:04 [Garlik] has SteveH, LukeWM 15:04:46 -prateek 15:05:36 Zakim, unmute me 15:05:36 KjetilK should no longer be muted 15:06:57 -AlexPassant 15:07:14 -SimonS 15:07:20 SimonS has left #sparql 15:07:34 most of the time I only need to "MINUS" a simple triple pattern, but the original use case needed a complex expression 15:08:07 what was the original use case? is it written down somewhere? 15:08:22 It was 5 years ago. :-) 15:08:57 what's the statute of limitations on use cases? :) 15:09:38 -kasei 15:10:00 It was along the lines of: select everyone who :worksFor a department, exception those people who have rdf:type :Student and who have not submitted their thesis (indicated by {?student :wrote ?thesis . ?thesis :docType :Thesis . ?thesis dc:published ?publishDate {) 15:10:01 -AndyS 15:10:03 -KjetilK 15:10:16 LukeWM has joined #sparql 15:10:24 -Lee_Feigenbaum 15:10:29 -[Garlik] 15:10:31 -pgearon 15:10:31 SW_(SPARQL)10:00AM has ended 15:10:32 Attendees were +1.216.445.aaaa, john-l, +3539149aabb, AndyS, AxelPolleres, +0005aacc, +1.312.863.aadd, KjetilK, kasei, bijan, SimonS, Lee_Feigenbaum, AlexPassant, SteveH, LukeWM, 15:10:34 ... +1.937.775.aaee, pgearon, EricP, prateek 15:10:59 Essentially, the use case came down to whenever a query selected something "Except" a particular set of things 15:11:21 The "except" was always an indicator 15:16:41 I wonder if a style difference is between negation over individuals (more MINUS centric?) and over triples? 15:17:19 That may be 15:17:21 Or another way for individuals is !EXISTS(SELECT ?X{...}) 15:18:51 negation over triples seems to concentrate on simple BGPs, while negation over individuals makes it more natural to remove a GroupGraphPattern 15:19:07 SteveH has joined #sparql 15:19:46 For individuals, yes, but it makes it hard if you need to remove things based on a tuple 15:20:16 though I've only ever run into the need for that once, and it was years ago 15:45:32 AxelPolleres has left #sparql 17:31:45 Zakim has left #sparql 17:38:54 SteveH has joined #sparql