15:59:10 RRSAgent has joined #rif 15:59:10 logging to http://www.w3.org/2008/12/16-rif-irc 15:59:18 zakim, this will be rif 15:59:18 ok, ChrisW, I see SW_RIF()11:00AM already started 15:59:20 DaveReynolds has joined #rif 15:59:27 rrsagent, make minutes 15:59:27 I have made the request to generate http://www.w3.org/2008/12/16-rif-minutes.html ChrisW 15:59:37 Chair: Chris Welty 15:59:39 -??P36 15:59:41 SW_RIF()11:00AM has ended 15:59:41 Attendees were 15:59:54 Meeting: RIF Telecon 16-Dec-2008 16:00:44 Agenda: http://lists.w3.org/Archives/Public/public-rif-wg/2008Dec/0090.html 16:00:58 ChrisW has changed the topic to: 16 Dec RIF Telecon Agenda http://lists.w3.org/Archives/Public/public-rif-wg/2008Dec/0090.html 16:01:11 SW_RIF()11:00AM has now started 16:01:15 +Sandro 16:01:19 +[IPcaller] 16:01:30 Zakim, IPCaller is me 16:01:30 +AxelPolleres; got it 16:01:40 StellaMitchell has joined #rif 16:02:44 +??P61 16:02:58 +[IBM] 16:03:03 zakim, ibm is temporarily me 16:03:03 +StellaMitchell; got it 16:03:14 +ChrisW 16:03:54 Hassan has joined #rif 16:03:56 josb has joined #rif 16:03:57 rrsagent, make logs public 16:04:14 zakim, who is on the phone? 16:04:15 AdrianP has joined #rif 16:04:21 +Hassan_Ait-Kaci 16:04:23 On the phone I see Sandro, AxelPolleres (muted), DaveReynolds, StellaMitchell, ChrisW, Hassan_Ait-Kaci 16:04:39 Scribe: DaveReynolds 16:04:50 ScribeNick: DaveReynolds 16:04:53 LeoraMorgenstern has joined #rif 16:05:23 Minutes from last time to be approved next call. 16:05:37 + +1.212.781.aaaa 16:05:39 TOPIC: Liason 16:05:47 + +39.047.101.aabb 16:05:49 zakim, aaaa is me 16:05:49 +LeoraMorgenstern; got it 16:06:20 yes 16:06:21 +??P75 16:06:26 Chris: meeting between OWL and RIF wg members last Thursday. Minutes were posted. 16:06:38 yes, Sandro sent to both lists 16:06:40 Zakim, ??P75 is me 16:06:40 +AdrianP; got it 16:06:44 Zakim, mute me 16:06:44 AdrianP should now be muted 16:06:45 + +43.158.801.3aacc 16:07:18 Chris: discussed four areas requiring some coordination. 16:07:33 Chris: (a) rdf:text reasonably well coordinated 16:07:44 Der, not as scribe, though HP comments on that. 16:08:06 Chris (b): OWL RL profile, could they use RIF syntax instead of arbitrary syntax? 16:08:31 zakim, 3aacc is temporarily me 16:08:31 sorry, Harold, I do not recognize a party named '3aacc' 16:08:40 Chris (c): datatypes, both have lists to be support, not a good reason for them to differ. 16:08:42 zakim, aacc is temporarily me 16:08:42 +Harold; got it 16:09:36 Chris: the discuss revealed that OWL have changed the interpretation of some of the data types, e.g. so that "1.0"^^xsd:float is an integer for OWL 16:10:01 Chris: and they have owl:real as a supertype of these modified types. 16:10:36 Chris: one implication is that the value spaces of the numeric types are not disjoint. 16:10:48 q+ 16:10:52 Gary_Hallmark has joined #rif 16:10:59 Chris: they have discussed this with xml schema representatives 16:11:32 + +1.503.533.aadd 16:11:33 Jos: have followed up with Boris, they are working with xml shema 1.1, not 1.0 as we do. 16:11:42 zakim, aadd is me 16:11:42 +Gary; got it 16:12:06 I was very surprised about that disjointness! :-o 16:12:27 section 2.2.3: 16:12:28 For purposes of this specification, the value spaces of primitive datatypes are disjoint 16:12:32 Minutes from the RIF/OWL coordination meeting are posted at: http://lists.w3.org/Archives/Public/public-rif-wg/2008Dec/0080.html 16:12:42 + +1.631.833.aaee 16:12:43 Michael_Kifer has joined #rif 16:12:52 Other applications making use of these datatypes may choose to consider values such as these comparable. 16:13:15 http://www.w3.org/TR/xmlschema11-2/#lexical-space 16:13:59 Dave, not as scribe, the float/integer mapping is far from trivial given over/underflow of mantissa. 16:14:46 Chris: fourth topic (d) RDF/OWL compatibility document, that is well in hand. 16:15:04 Jos: all the proposals for changes to SWC were accepted. 16:15:35 Chris: so remaining issues are OWL RL rules and datatypes 16:16:51 Chris: OWL RL RIF rules could be in OWL profile document, separate document or in SWC 16:17:16 Sandro: the first would require making RIF syntax palatable to OWL readership, which may be a challenge 16:17:56 Sandro: also the issue of how to handle to list rules which are done as templates in OWL RL rather than by explicit rules 16:18:24 Sandro: try to create a proposal which is acceptable to OWL may be not be possible 16:18:45 Chris: people agreed that the XML form of rules should be available via link but not inline in document 16:18:48 remark: some similar issues concerning xs:string vs rdf:text raised by Andy Seaborne... /me looking for the mail document 16:18:53 moment 16:19:48 q+ 16:19:54 right, in OWL xsd:string is a subtype of rdf:text, but in RIF this is not the case 16:19:56 q- 16:20:02 ack dave 16:20:25 ...and the binaries 16:21:10 q+ 16:21:40 Dave: three datatype issues rdf:text, list of types, numeric type differnces 16:21:44 action: chris to open rdf:text issue 16:21:44 Created ACTION-674 - Open rdf:text issue [on Christopher Welty - due 2008-12-23]. 16:22:01 Dave: for rdf:text then there are issues with stated change to RDF and implicit change to SPARQL 16:22:02 ack jos 16:22:28 Dave: can be resolved with small changes to text, Andy Seaborne and Dave Reynolds have a suggestion for this 16:23:09 Jos: there is also the issue the rdf:text also reinterprets xs:string as a subtype of rdf:type, this is also an incompatibility but is already an open issue 16:23:24 Jos: this would again have issues for RDF compatibility 16:24:14 +1 for treatment of string as subtype of text 16:25:15 action: chris to open issue on string subclassOf rdf:text 16:25:15 Created ACTION-675 - Open issue on string subclassOf rdf:text [on Christopher Welty - due 2008-12-23]. 16:26:05 q? 16:26:43 Chris: for the list of datatypes which share/don't share just taking union would probably be fine 16:26:45 q+ 16:27:00 Dave: reuse of rdf: namespace is not the problem, just wording that would imply that rdf should support rdf:text... if we exclude that explicitly from rdf we should be fine. 16:27:10 (hope I got that right) 16:27:27 there are more differences.... 16:27:27 Sandro: subtypes of string is also an issue (regexp defined subtypes of strings) 16:28:00 Sandro: implementation burden, maybe not a big one, but have to decide whether to include and if not then push back on OWL 16:28:03 q+ 16:28:06 q- 16:28:52 q- 16:29:15 ... if we add also respective predicates and functions for other datatypes, it will mean considerable effort for DTB, deciding on which preds/functions we want, etc. 16:29:16 Jos: there are more different types such as the binary types (xsd:hexbinary), also owl:datetype which need to be decided upon 16:29:30 ... that is just a remark, not an objection. 16:29:42 s/datetype/dateTime/ 16:30:09 Chris: we should compile the definitive list of differences, decide what RIF wants to support and go back to OWL 16:30:26 Sandro: there are two lists in OWL, the full list of datatypes and the subset for OWL RL 16:30:37 Sandro: could restrict the RIF/OWL agreement to just those for OWL RL 16:30:48 Jos: OWL RL already includes many of the tough ones! 16:31:04 http://www.w3.org/TR/2008/WD-owl2-profiles-20081202/#Entities_3 16:31:11 Sandro: need to weigh benefits to user against cost of implementation 16:31:17 do OWL know how to implement these? 16:31:22 q+ 16:31:45 Sandro: not clear how much user pull there is for all of these 16:32:04 ack d 16:33:32 Dave: there is also the issue of what builtins are needed for each of these datatypes to make them useful in RIF 16:34:03 Axel: the other schedule risk is whether this is a moving target 16:34:20 Sandro: OWL is at last call, though the specific list for OWL RL is "at risk" 16:34:34 q+ 16:34:46 ... if all is fixed, and only equality is required, then we should be fine!? 16:34:56 Axel: could have minimal inclusion just support equality which is all OWL need but not a rich library of associated builtins 16:35:22 Jos: regarding the numerics, inclined to go OWL route, easier for users and elegant 16:35:26 q- 16:35:44 Sandro: hesitant, depends on user community - programmers v. logic folk 16:35:47 q+ 16:36:43 q- 16:36:51 TOPIC: Public Comments 16:37:02 Dave: concerned about implementation cost of the float/integer equivalence when handling under/overflow of mantissa 16:37:22 Chris: updated to RAK, people should look at this 16:37:53 Chris: one comment missed up to now, question concerns value space for rif:local and implementation advice 16:37:53 ok 16:38:19 TOPIC: F2F12 16:38:28 Dave, what is your feeling about non-disjointness of hexBinary and base64Binary? 16:39:00 Dave (not as scribe) to jos: I think that's fine, they are just serializations of binary 16:39:25 rif:local is not a datatype, so it also doesn't have a value space... not sure how I should read that question... will have a look though. 16:39:26 OK, so for these types we don't have a problem with going the OWL way 16:39:32 action: sandro to set up poll for f2f12 16:39:35 action: sandro to set up registration for F2F12 16:39:44 s/for/form for/ 16:39:53 trackbot has joined #rif 16:40:15 can someone paste the link to the respective mail? (concerning rif:local value space) 16:40:16 Chris: a number of people likely to attend remotely, so we should know how many 16:40:38 Sandro: wonders whether to explore video conferencing option 16:40:55 http://lists.w3.org/Archives/Public/public-rif-comments/2008Nov/0000.html 16:42:56 Gary: not aware of any video conference support in the facility 16:43:03 action: to look into videoconf support for F2F12 16:43:03 Sorry, couldn't find user - to 16:43:10 action: Gary to look into videoconf support for F2F12 16:43:10 Created ACTION-676 - Look into videoconf support for F2F12 [on Gary Hallmark - due 2008-12-23]. 16:43:21 TOPIC: Holiday schedule 16:43:29 zakim, who is here? 16:43:29 On the phone I see Sandro, AxelPolleres, DaveReynolds, StellaMitchell, ChrisW, Hassan_Ait-Kaci (muted), LeoraMorgenstern, josb, AdrianP (muted), Harold, Gary, +1.631.833.aaee 16:43:32 On IRC I see trackbot, Michael_Kifer, Gary, LeoraMorgenstern, AdrianP, josb, Hassan, StellaMitchell, DaveReynolds, RRSAgent, Zakim, ChrisW, Harold, AxelPolleres, sandro 16:43:52 zakim, aaee is Michael_Kifer 16:43:52 +Michael_Kifer; got it 16:44:31 For H.323 clients, NRC colleagues suggest XMeeting on Mac or Net Meeting or Polycom PVX for the PC. 16:44:45 I used Net Meeting successfully. 16:44:55 Poll: if we have a telecon Dec 23, would you attend 16:45:00 +1 16:45:00 Show of hands for telecon on 23rd: 16:45:02 -1 16:45:03 +1 16:45:04 +1 16:45:06 -1 16:45:07 +1 16:45:10 -1 16:45:10 -1 16:45:11 +1 16:45:17 -1 16:45:19 -1 16:45:24 :-) 16:45:31 +1 from my desk 16:45:43 Show of hands for telecon on 30th: 16:45:44 Poll: if we have a telecon Dec 30, would you attend 16:45:48 -1 16:45:49 -1 16:45:50 -1 16:45:51 -1 16:45:53 -1 16:45:54 -1 16:46:03 -? 16:46:07 0 (not yet sure) 16:46:10 0 16:46:34 Telecon next week (Dec 23) 16:46:40 cancel telcon Dec 30 16:47:03 TOPIC: Publications 16:47:30 Zakim, unmute me 16:47:30 AdrianP should no longer be muted 16:47:36 Sandro: publications waiting on PRD 16:48:45 Adrian: still discussing a question on semantics and whether to publish now or change it 16:49:14 Adrian: Christian making a change (not finished as of 1 hour ago) 16:49:40 Poor girl! :-) 16:49:53 TOPIC: Action Review 16:49:59 ChrisW: is your daughter joining as invited expert or for IBM? 16:50:09 Adrian: probably finalize at PRD telecon 16:50:56 yes 16:51:04 Action-669 closed 16:51:05 ACTION-669 Incorporate and address Jos' comments from http://lists.w3.org/Archives/Public/public-rif-wg/2008Nov/0190.html closed 16:51:28 Action-666 will finish tomorrow 16:52:18 Action-604 to pending review 16:52:27 continued 16:52:36 (I'll get to it over the break.) 16:52:55 Action-588 continued 16:53:11 on 16:53:44 TOPIC: ACTION-635: RDB2RDF and RIF [17], [11] (10 mn) 16:53:52 that's done 16:53:56 it is an XG 16:54:47 q+ 16:54:48 Axel: at the moment nothing more required 16:55:25 q? 16:55:25 TOPIC: DTB 16:55:44 q- 16:56:42 Chris: DTB four issues - negative guards, more general guards, additional OWL-RL datatypes, string predicates 16:57:22 q+ 16:57:30 We don't have odditional datatypes yet mentioned in as an issue in the document. 16:57:54 Jos: regarding negative guards and discussion with Sandro on list ... 16:58:54 Jos: Sandro suggested that in practice will be implemented using some external oracle which can report yes/no/unknown for constant 16:59:51 Jos: could have an isLiteral guard so that then with the isLiteral guard could always decide yes/no for the guards like isInteger 17:00:07 Chris: is this explicit in rules or implied by implementation? 17:00:14 Jos: explicit in rules 17:00:43 Sandro: do the use cases for negative guards need this isLiteral guard? 17:01:02 Jos: this isLiteral is just to prevent reasoners having to do case analysis 17:01:24 Sandro: never have to do case analysis over externals 17:01:58 Jos: so does that imply changing the semantics of the guards to only apply to such concrete values 17:02:16 Jos: that's what we did for positive guards but didn't work for negative guards 17:02:33 neither guards not neg guards have a domain specified! 17:02:56 Jos: the external functions don't know about the abstract objects in the domain and so can't be reasoned about by external functions 17:03:06 q? 17:03:10 ackj 17:03:14 ack j 17:03:36 guards were intended to be defined for everything. 17:03:39 Sandro: not proposing restricted domain, guards are defined for everything, but result might not always be known 17:03:55 as they are defined now, they cannot return "unknown" 17:04:38 q+ 17:04:42 Sandro: suggesting that external predicates should be allowed to return unknown 17:05:25 isDATATYPE means that the argument is *known* to be in the value space. 17:05:31 q? 17:05:33 Sandro: handles the test cases discussed in email so ex:a would match neither isInteger nor isNotInteger given no other information 17:05:51 what about rasing an exception? 17:05:54 Chris: does this require another truth value 17:06:00 s/ras/rais/ 17:06:11 but then we would need a three-valued truth logic 17:06:14 Sandro: to the external predicates but not the BLD semantics 17:06:37 q- 17:06:55 in the case of BLD, it's more like isKnownToBeInteger, and isKnownToNotBeInteger. 17:07:17 isnotknowntobeinteger is the current semantics 17:07:40 sandro: Yes, I think in BLD, the positive and negative guards would return false on non-literals. 17:07:43 Chris: so the negative guards would return false on non-literals 17:07:43 (for isNotInteger being true) 17:08:38 ex:a = 3 , isInteger(ex:a) 17:08:41 q+ 17:09:21 csma has joined #rif 17:09:35 Sandro: then would expect the answer from isInteger to be true but with his proposal the the builtin wouldn't know this and so would still return unknown which BLD turns into false 17:09:51 Sandro: then the reasoner would later call isInteger on 3, substituting for ex:a and then return true 17:10:31 +??P6 17:10:40 zakim, ??P6 is me 17:10:40 +csma; got it 17:10:46 zakim, mute me 17:10:46 csma should now be muted 17:11:18 we need them for embedding of OWL 2 RL, for example 17:11:41 Axel: the intention was that the negative guards should be the exact inverse of the positive guards for the original use case, this solution would not satisfy that 17:11:54 (but a workaround might be possible) 17:11:54 Axel: [gave example but scribe missed it] 17:13:01 Sandro: not convinced that case is really needed in BLD, is it just about handling bad data 17:13:03 q? 17:13:09 ack AxelPolleres 17:13:17 q? 17:13:19 q+ 17:13:24 I think the use case was about working around errors 17:13:42 ack dave 17:13:58 would OWL RL be fine with modeling negative guards in NAF? 17:14:19 DaveReynolds: OWL-RL needs negative guards, so it can test for all literals being equal/not-equal to each other. But an isLiteral guard might do it. 17:14:24 s/OWL RL/the OWL RL translation/ 17:14:45 isInteger, and isNonIntegerLiteral. 17:15:14 I would like to have the rdfs:Literal, in any case 17:15:25 Dave: and OWL-RL needs negative type check for validation but that may only apply to the explicit literals, would need to check that 17:15:52 s/only/only need/ 17:16:00 q+ 17:17:05 maybe it would be easier to extend the semantics and introduce a typed logic 17:17:10 Jos: current OWL embedding uses negative guards in two places, one to check it is a literal at all, might be able to work around by axiomatize somehow 17:17:22 with sorts for Integer, String etc. 17:17:41 Jos: adding constraint of returning "no" for non-literals would break things in this case 17:18:13 +1 with Jos 17:19:10 Jos: negative guards are a problem, and this modified semantics is rather unintuitive and perhaps not of use 17:19:18 Option-1: get rid of negative guards entirely 17:19:36 Option-2: switch to "isNonIntegerLiteral" 17:20:01 Option-3: requiring rules to use isLiteral guard before the negative guards 17:20:34 Option-4: leave it the way it is --- you have to reason by cases 17:21:05 I have a doubt about the usefulness of Option-2. and I further have the impression that Option-4 could simply be emulated by Option-1 + naf. 17:21:11 Option-5: drop specific-type negative guards, but keep isNotLiteral 17:21:14 would also require reasoning by case 17:21:34 is that observation correct? 17:22:04 isLiteral can be emulated by a single rule with a disjunctive body. 17:22:19 Michael: option-3 is not interesting because it puts the burden on the user 17:22:34 I need to think about it some more. 17:22:40 Axel: classical negation != naf 17:22:42 Straw poll on these options: 17:22:54 preference: 1 or 4 before all other options. 17:22:55 Option-1 17:22:57 1 17:23:01 (not as scribe) probably 2 17:23:01 Option-1 17:23:03 1 or 2 17:23:03 (I cannot give a total order) 17:23:05 Optin 1 17:23:10 1 17:23:21 maybe 17:23:59 Chris: would anyone argue strongly for having negative guards in? 17:24:06 dave, the OWL RL encoding wouldn't work without any form of negation (be it guards or naf), right? 17:24:10 I suspect that most implementations would map guards to a fully typed logic anyway 17:24:32 (not as scribe) Axel - right, hence my vote for 2 17:24:43 q+ 17:24:47 Chris: seems like folks are leaning toward removing negative guards. 17:24:54 Axel, Dave, one can axiomatize negative guards 17:24:57 what about option-1 and moving the OWL RL encoding to a naf dialect? 17:25:27 q- 17:25:44 axiomatization will be there in < 2 weeks 17:26:02 DaveReynolds: I don't see how to do OWL-RL without negative guards, so let's see if someone can figure out a way to do it. 17:26:44 zakim, unmute me 17:26:44 csma should no longer be muted 17:27:02 Topic: back to publication and PRD draft 17:27:36 csma: not happy with the semantics on conditions and would like it to be reviewed by someone else before publication 17:28:10 csma: all other changes done, may not be fit for proving PRD is an extension of Core but at least that section should be easier to understand 17:28:54 Chris: could we publish as is and if necessary revise for next WD? 17:29:24 csma: not a show stopper, can publish yes, but want to make it easier to understand 17:30:04 csma: believe made all the edits, may be some links that need fixing after translation to TR 17:30:09 we could add some references to standard definitions such Herbrand Interpret. etc. 17:30:20 Chris: unleashes Sandro to do the publication! 17:30:35 -Hassan_Ait-Kaci 17:30:36 -LeoraMorgenstern 17:30:37 Chris: reminder there will be a telecon next week but 30th is cancelled 17:30:38 -Gary 17:30:39 -StellaMitchell 17:30:42 -AxelPolleres 17:30:45 zakim, list attendees 17:30:45 As of this point the attendees have been Sandro, AxelPolleres, DaveReynolds, StellaMitchell, ChrisW, Hassan_Ait-Kaci, +1.212.781.aaaa, +39.047.101.aabb, LeoraMorgenstern, AdrianP, 17:30:49 ... +43.158.801.3aacc, Harold, josb, +1.503.533.aadd, Gary, +1.631.833.aaee, Michael_Kifer, csma 17:30:52 -Harold 17:30:52 -Michael_Kifer 17:30:52 -AdrianP 17:30:52 -josb 17:31:12 Regrets: PaulVincent 17:31:22 rrsagent, make minutes 17:31:22 I have made the request to generate http://www.w3.org/2008/12/16-rif-minutes.html ChrisW 17:32:20 -DaveReynolds 17:34:00 -ChrisW 17:34:02 -Sandro 17:34:02 -csma 17:34:03 SW_RIF()11:00AM has ended 17:34:05 Attendees were Sandro, AxelPolleres, DaveReynolds, StellaMitchell, ChrisW, Hassan_Ait-Kaci, +1.212.781.aaaa, +39.047.101.aabb, LeoraMorgenstern, AdrianP, +43.158.801.3aacc, Harold, 17:34:08 ... josb, +1.503.533.aadd, Gary, +1.631.833.aaee, Michael_Kifer, csma 18:05:36 Gary_Hallmark has joined #rif 18:06:53 csma has left #rif 19:39:46 Zakim has left #rif