15:48:07 RRSAgent has joined #rif 15:48:07 logging to http://www.w3.org/2007/12/18-rif-irc 15:48:24 zakim, this will be rif 15:48:24 ok, csma; I see SW_RIF()11:00AM scheduled to start in 12 minutes 15:48:46 Meeting: RIF telecon 18 December 2008 15:48:53 Chair: Christian de Sainte Marie 15:49:15 Agenda: http://lists.w3.org/Archives/Public/public-rif-wg/2007Dec/0081.html 15:49:44 Scribe: Hassan Haït-Kaçi 15:49:55 Scribenick: hak 15:50:46 csma has changed the topic to: 18 Dec RIF telecon agenda: http://lists.w3.org/Archives/Public/public-rif-wg/2007Dec/0081.html 15:50:56 zakim, list agenda 15:50:56 I see 2 items remaining on the agenda: 15:50:57 6. BLD - Issue 43 [from ChrisW] 15:50:58 7. AOB [from ChrisW] 15:51:04 zaki, reset agenda 15:51:11 zakim, list agenda 15:51:11 I see 2 items remaining on the agenda: 15:51:12 6. BLD - Issue 43 [from ChrisW] 15:51:13 7. AOB [from ChrisW] 15:51:23 zakim, close agenda 15:51:23 I don't understand 'close agenda', csma 15:52:03 zakim, clear agenda 15:52:03 agenda cleared 15:52:54 patranja has joined #rif 15:53:35 agenda+ Admin 15:53:45 agenda+ Liaisons 15:54:30 agenda+ Issue 40 (builtins) 15:54:55 agenda+ Issue 44 (named argument uniterms) 15:55:07 agenda+ Issue 45 (lists) 15:55:24 agenda+ AOB (pick scribe for next week!) 15:57:25 Harold has joined #rif 15:58:38 Hassan has joined #rif 15:59:32 SW_RIF()11:00AM has now started 15:59:33 +Hassan_Ait-Kaci 16:00:40 +??P16 16:00:42 -??P16 16:00:42 +??P16 16:00:44 IgorMozetic has joined #rif 16:00:55 ChrisW has joined #rif 16:01:23 +??P28 16:01:33 StellaMitchell has joined #rif 16:01:40 zakim, P16 is temporarily me 16:01:40 sorry, Harold, I do not recognize a party named 'P16' 16:01:46 zakim, ??P28 is me 16:01:46 +csma; got it 16:01:52 +??P32 16:01:53 zakim, ??P16 is temporarily me 16:01:53 +Harold; got it 16:02:03 zakim, ??P32 is me 16:02:03 +IgorMozetic; got it 16:02:10 zakim, mute me 16:02:10 IgorMozetic should now be muted 16:02:27 +Stella_Mitchell 16:02:45 zakim, who is on the phone? 16:02:47 On the phone I see Hassan_Ait-Kaci, Harold, csma, IgorMozetic (muted), Stella_Mitchell 16:02:59 +ChrisW 16:03:30 scribenick: Hassan_Ait-Kaci 16:03:54 +??P46 16:03:57 LeoraMorgenstern has joined #rif 16:04:23 (I will just be on tthe IRC for a while; stuck in a meeting.) 16:04:59 zakim, who is on the phone? 16:04:59 On the phone I see Hassan_Ait-Kaci, Harold, csma, IgorMozetic (muted), Stella_Mitchell (muted), ChrisW, ??P46 16:05:18 zakim, ??P46 is PaulaP 16:05:19 I already had ??P46 as PaulaP, csma 16:05:54 zakim, take up item 1 16:05:54 agendum 1. "Admin" taken up [from csma] 16:05:59 zakim, list agenda 16:06:02 I see 6 items remaining on the agenda: 16:06:04 1. Admin [from csma] 16:06:06 2. Liaisons [from csma] 16:06:10 3. Issue 40 (builtins) [from csma] 16:06:12 4. Issue 44 (named argument uniterms) [from csma] 16:06:16 5. Issue 45 (lists) [from csma] 16:06:18 6. AOB (pick scribe for next week!) [from csma] 16:06:27 No agenda amendments ... 16:06:42 +??P59 16:06:44 +Gary_Hallmark 16:06:53 -??P59 16:06:56 AxelPolleres has joined #rif 16:06:57 Accepting last week's minutes postponed to next week? 16:07:04 PROPOSED: accept the minutes of December 4 telecon 16:07:10 Propose to accept those of Dec 4 2007 telecon 16:07:38 http://lists.w3.org/Archives/Public/public-rif-wg/2007Dec/att-0050/04-rif-minutes.html 16:07:56 +Sandro 16:07:57 zakim, who is on the phone? 16:07:58 On the phone I see Hassan_Ait-Kaci, Harold, csma, IgorMozetic (muted), Stella_Mitchell (muted), ChrisW, PaulaP (muted), Gary_Hallmark, Sandro 16:08:07 RESOLVED: accept the minutes of Dec 4 2007 16:08:15 +??P65 16:08:27 Zakim, P65 is me 16:08:27 sorry, AxelPolleres, I do not recognize a party named 'P65' 16:08:33 Zakim, ??P65 is me 16:08:33 +AxelPolleres; got it 16:09:03 Sandro, What were the highlights of the OWL f2f most relevant to RIF? 16:09:04 Christian worries about posting of meetings early enough... 16:09:17 Merry everything ... :-) 16:09:22 GaryHallmark has joined #rif 16:09:57 Action 394 done 16:10:32 Action 395 done 16:10:53 http://www.w3.org/2005/rules/wg/wiki/Response_to_PPS1?action=diff&rev2=9&rev1=8 16:11:06 Harold says see Wiki for Action 395 16:11:28 Harold comments his changes in the document 16:11:46 Ask MK to review the changes ... 16:12:23 next agendum 16:12:34 zakim, close item 1 16:12:34 agendum 1, Admin, closed 16:12:35 I see 5 items remaining on the agenda; the next one is 16:12:37 2. Liaisons [from csma] 16:12:47 What were the highlights of the OWL f2f most relevant to RIF 16:12:55 Igor worries about OWL F2F meeting in Manchester... 16:13:05 ^Igor^Harold 16:13:11 Sandro was there ... 16:13:17 s/worries/wonders/ 16:13:38 Sandro does not have anything to report 16:13:59 Harold worries about overlapping dates with other events 16:14:26 Sandro says that no decision in the OWL WG regarding this has been taken so far 16:14:40 Just getting the basics to get the WG going 16:14:48 s/Harold worries about overlapping dates with other events/Harold wonders about DL safe rules in OWL/ 16:16:26 RIF/OWL task force (Peter Patel-Schcheider and Uli Sattler on the OWL side and Mike Dean and Jos Debruijn on ours 16:16:43 Any othet liaison? 16:16:46 None 16:16:51 next agendum 16:16:53 s/othet/other/ 16:17:17 http://www.w3.org/2005/rules/wg/track/issues/40 16:17:17 Issue 40 - about builtins 16:17:37 http://www.w3.org/2005/rules/wg/wiki/List_of_BLD_built-ins 16:17:46 last week the syntax for evaluated preds and funcs was resolved 16:18:03 this week we need to discuss the rest 16:18:25 item: what builtins for BLD? 16:18:41 http://www.w3.org/2005/rules/wg/wiki/List_of_BLD_built-ins 16:18:46 proposal: include all that in the builtin page? 16:19:01 s/builtin/builtins/ 16:19:03 PROPOSED: BLD builtins will at least include those being currently 16:19:03 listed on the builtins page 16:19:23 q? 16:20:19 Paula: the status of some of them needs to be discussed because many have proposed sets of builtins 16:20:32 csma: since the others are not here ... 16:20:32 zakim, close item 2 16:20:32 agendum 2, Liaisons, closed 16:20:33 I see 4 items remaining on the agenda; the next one is 16:20:34 3. Issue 40 (builtins) [from csma] 16:21:13 csma: there 3 sets (1) numerics (2) strings (3) date and time 16:21:55 csma: idea is not to exclude anything but to decide the mininum set we need 16:22:41 PROPOSED: BLD builtins will at least include those currently being listed in the "list of supported builtins" section of the buildin page 16:23:28 ChrisW: this is hard to record 16:23:40 Sandro: put a link to the front of the page 16:23:45 markproctor has joined #rif 16:24:31 May I remind of conversion functions... just came to my mind again: 16:24:31 csma: there is a level of indirection in the links 16:24:32 http://lists.w3.org/Archives/Public/public-rif-wg/2007Jun/0003.html 16:25:04 +Mark_Proctor 16:25:19 sorry I'm late, was in another call previously. 16:25:22 Sandro: proposes "this is the list of builtins in the next working draft..." (sorta...) 16:25:22 I think it is this link: http://www.w3.org/2005/rules/wg/wiki/List_of_BLD_built-ins?action=recall&rev=23 16:26:53 http://www.w3.org/2005/rules/wg/wiki/Functions_and_Operators_on_Numerics 16:27:09 ChrisW proposes the add the links to the three pages of proposed builtins 16:27:27 http://www.w3.org/2005/rules/wg/wiki/Functions_on_Strings 16:27:30 s/the/to/ 16:27:32 http://www.w3.org/2005/rules/wg/wiki/Functions_and_Operators_on_Dates_and_Times 16:27:49 (implicit ?action=recall&rev=1 to each of those) 16:28:18 ChrisW: propose to put an action on someone to fix it 16:29:01 Sandro: propose the action tto be to put it into a TR document 16:29:07 Paula? 16:29:17 s/tto/to/ 16:31:24 MoZ has joined #rif 16:31:28 MichaelKifer has joined #rif 16:31:40 Current appendix: 16:31:41 http://www.w3.org/2005/rules/wg/wiki/Core/Specification 16:32:13 +MichaelKifer 16:32:35 Action on Harold to fix the document(s) accordingly 16:32:52 Action: Harold to add builtin page as a new appendix to BLD 16:32:52 Created ACTION-397 - Add builtin page as a new appendix to BLD [on Harold Boley - due 2007-12-25]. 16:32:56 zakim, mute me 16:32:56 MichaelKifer should now be muted 16:34:00 csma: anyone objecting to the notion of having the current list of builtins in the BLD 16:34:10 should speak up 16:34:20 q? 16:34:51 zakim, unmute me 16:34:51 MichaelKifer should no longer be muted 16:34:56 csma: if we do we may also want functions in addtion to predicates? 16:35:04 MK: what semantics? 16:35:19 s/addtion/addition/ 16:35:28 q+ 16:36:28 MK: functions as builtins require a notion of error ... 16:36:47 are all the proposed builtins total functions? (Has anyone checked?) 16:37:01 csma: using a predicate notation ? 16:37:09 LeoraM has joined #rif 16:37:17 MK: then error will mean failure (false) 16:37:42 +[IBM] 16:37:48 zakim, ibm is temporarily me 16:37:48 +LeoraM; got it 16:37:53 zakim, mute me 16:37:53 LeoraM should now be muted 16:38:32 P(f(a)) = P(x) AND Pf(x a) 16:38:35 what about designating a special URI as a return value ? 16:38:41 Hassan: I can write you a semantics for functions, with errors, with no problem. I don't see the difficulty here. 16:39:16 MichaelKifer: But we have functional expressions. We'll have to explain how to unwrap these functional expressions. This gets complicated. 16:39:22 e.g. rif:error 16:39:35 as a return value when a function fails 16:40:08 MichaelKifer: csma, your approach make sense, but then what happens when you apply a function to a function? It's not *BIG* problem, but we'll have to do something about it. 16:40:15 q? 16:40:25 q+ 16:40:31 Hassan: Sorry, why is applying a function to a function a problem? 16:40:38 Michael, P(g(f(a))) = P(x) AND f(x y) AND f(y a) 16:40:53 ack axel 16:41:00 s/ Michael, P(g(f(a))) = P(x) AND f(x y) AND f(y a)/ Michael, P(g(f(a))) = P(x) AND g(x y) AND f(y a) 16:41:03 MichaelKifer: We'll have to explain that functions are syntactic sugar for predicates, and we'll have to explain how you unwrap them to predicates. 16:41:09 s/ Michael, P(g(f(a))) = P(x) AND f(x y) AND f(y a)/ Michael, P(g(f(a))) = P(x) AND g(x y) AND f(y a)/ 16:41:24 (no problem, hassan. I was trying to tell you I would scribe while you spoke, but was muted.) 16:41:28 http://lists.w3.org/Archives/Public/public-rif-wg/2007Jun/0003.html 16:41:34 Axel: functions are needed for conversions (from one type to another) 16:42:11 MK: still is not convinced - it needs work 16:42:15 MichaelKifer: the unary function examples are simple; it gets more complicated, and will take a page or so. 16:42:26 P(g(f(a1 ... anN))) = P(x) AND g(x y) AND f(y a1 ... anN) 16:42:36 MichaelKifer: similar to the text about frames, but more complex. 16:42:46 Hassan: All functions are unary, by Currying. 16:43:13 Hassan: Many arguments is one argument, etc. 16:43:31 Hassan, do you really propose Currying for RIF? 16:43:34 q? 16:43:39 MK: needs to explain more 16:44:08 (http://en.wikipedia.org/wiki/Currying) 16:44:12 ChrisW: we could require that external functions calls be total functions 16:44:27 MK: cannot garantee that 16:45:51 But, again, I support Michael, let's omit functions in RIF 1.0 FOR MAKING THINGS NOT MORE COMPLICATED. 16:45:58 MK: argues that one cannot define the semantics of the predicate upon functional error 16:46:25 * Functions would call for Equality (and not all people don't want that) 16:46:41 q? 16:46:43 * We would have a predicate/function duplication of builtins 16:46:57 ack chrisw 16:47:44 harold: wonders about equality of functions 16:48:06 harold: it complicates things 16:48:55 q? 16:49:10 Once you have builtin functions like plus and square, then people will ask for user-defined functions like sumofsquare(?L) = ... 16:49:18 (and we need equality) 16:49:52 csma: we would need to explain how we unwrap predicates as functions for the semantics ... 16:49:57 MK: sure ... 16:50:50 MK: how to name the introduced predicates? all this need to be mad explicit ... 16:51:01 s/mad/made/ 16:51:42 MK: if functions are syntactic sugar, we need to give the semantics of the "real" thing they stand for 16:52:09 csma: but some systems using BLD might have both functions and predicates 16:52:24 MK: that's a problem 16:52:39 I would like user defined functions 16:52:51 in BLS, they are fine, in CORE no... if we get there. 16:52:59 s/BLS/BLD/ 16:53:05 csma: functions are useful because many languages have them 16:53:08 Hi Gary, so do you like Equal in BLD? 16:53:21 harold: yes 16:53:23 +1 for having them 16:53:33 MK: not objecting to functions, just that they add complications 16:53:51 Gary, OK it's still in there (but not in what we thought would be the Core). 16:54:05 for PRD, perhaps all functions are builtin or user-defined 16:54:12 MK: needs to make the syntactic sugar unwrap and what the eventual things are must be made clear 16:54:13 I see 16:54:19 Gary. 16:55:34 PROPOSED: Built-in functions will have corresponding built-in predicates, and the built-in functions will be treated as syntactic sugar for the corresponding built-in predicates. 16:56:13 q? 16:56:22 Hassan: The basic syntactic sugar of CLP is all you need here. 16:56:51 Hassan: The constraints should have the capacity of being well-denoting expressions. 16:58:01 MichaelKifer: If we only dealt with rule languages this wouldn't be a problem, but when you think about extending to FOL, well.... I'm avoid making committments which complicate that. Once we decide to translate differently in the Head vs Body, then we break the idea of BLD being a subset of FOL. 16:59:14 MichaelKifer: The constraint is a conjunct? 16:59:25 Hassan: The constraint is anything. It can be an oracle. 16:59:41 MichaelKifer: So the FOL dialect would have to be a "constraint FOL" ? 16:59:58 Hassan: No, the constrain is just a relation. 17:00:39 MichaelKifer: A constraint is a formula, right? ( a predicate, a relation ) How is it going to be related to the main formula? A conjunct or what? 17:01:03 p(f(a)) :- body -> p(x) :- body AND x = f(a) 17:01:18 Hassan: You don't need to worry about that. The connection is just the shared variables. This is explained very clearly in @@@ 17:02:44 seems to me we've gotten off track 17:05:59 MK: functions appearing in the head of a rule makes things complicated 17:07:39 functions treated as syntactic sugar for predicates cause problems in the head, and will complicate an extension to e.g. FOL? 17:09:25 a better semantic match for my PR engine is to model a distinguished "error" element in the domain 17:09:46 q? 17:10:11 I agree that built-ins (functions or predicates, both I assume) in head are problematic 17:10:44 Can we just outlaw builtins in the head? 17:11:08 q+ 17:11:11 i already proposed this - csma didn't like 17:11:13 We can safely disallow them in heads. so what's the problem? 17:11:39 +1 to disallow in head 17:11:50 i like keeping bld a subset of FO 17:12:01 (as do I) 17:12:29 ack sandro 17:13:03 sandro: what does csma need bi's in the head? 17:13:27 We talk about built-ins, not actions!!! 17:14:14 a function or predicate is something with a fixed semantics, not something which changes the world 17:14:23 you talk about := not about == 17:14:48 Ah - I get it. If p(x) then q(f(x)) 17:15:15 :) 17:15:35 sorry my other phone went off 17:15:48 I don't understand why this is built-ins still. 17:15:53 Christian's example without introducing Equal: p(f(a)) :- body -> p(x) :- body AND f(x a) 17:16:04 q+ 17:16:06 q? 17:16:11 ack axel 17:16:40 Well, BLD doesn't do a lot of useful things 17:17:54 if p(x) AND y=f(x) THEN q(y) 17:18:08 If you would expand christian's example to predicates as discussed before, the actual builtin call would be in the body. 17:18:16 yup. 17:18:48 csma: is reluctant to pass a resolution on this now 17:20:01 Gary Hallmark: just treat undefined as an exception -> maps the value of the predicate to false 17:21:32 Gary, Michael, in "strict" functional languages an error element raised somewhere makes all enclosing expressions into errors. 17:21:40 MK: need a different semantics to treat undefined (special URL?), then what this denotes 17:22:11 csma: how do the FOL rule languages deal with this? 17:22:29 MK: they don't - they issue an error - it is not in the semantics 17:22:46 i'm not sure we need to have a model theory for errors 17:23:27 csma: summing up - we want functions (maybe in the head) and semantics of error 17:23:49 ChrisW: we don't need to account for erro model-theoretically 17:23:59 s/erro /error / 17:24:14 If we want to be "strict", then we need something equivalent to saying f(a1,...,aJ-1,error,aJ+1,...,aN) = error for all f. 17:24:33 MK: if so, then we need to restrict the use of functions to reach a meaningful compromise 17:24:54 csma: why not flag it as an error? 17:25:38 MK: then it would be a syntactic issue, but with BI's you can't do this because not all is statically verifiable 17:26:09 MK: we need to define the meaning of the expression when evaluating it gave an error 17:26:11 The "Catch" operator is "non-strict". 17:26:43 Catch(a1,...,aJ-1,error,aJ+1,...,aN) != error 17:27:26 (see http://en.wikipedia.org/wiki/Functional_programming) 17:27:48 ChrisW: did we really mean to treat error in FOL as well? I do not think that it should be boggle us down ... we can do semething else 17:28:11 q? 17:28:16 MK: what "something else"? 17:28:35 s/semething/something/ 17:29:21 csma: looking for a victim ... :-) 17:29:24 bye... 17:29:45 -PaulaP 17:29:52 Paula and All, I did my ACTION-397: http://www.w3.org/2005/rules/wg/wiki/Core?action=diff&rev2=64&rev1=63 (I hope you are fine with the spelling of "builtin") 17:30:11 -ChrisW 17:30:50 :) 17:31:09 MK: proposes to put the burden of having function symbols on the translator (they define the synctatic surgar they mean) 17:31:17 BLD+-+-- 17:31:43 +1 17:31:54 Dear Santa, please bring me a model theory for errors 17:31:58 csam: proposes to adjourn 17:32:12 s/csam/csma/ 17:32:13 :-) 17:32:19 -IgorMozetic 17:32:21 -Gary_Hallmark 17:32:23 -MichaelKifer 17:32:26 -Harold 17:32:29 -Stella_Mitchell 17:32:29 bye all happy new year! 17:32:34 happy december, everyone 17:32:36 rrsagent, make log public 17:32:37 zakim, list attendees 17:32:37 As of this point the attendees have been Hassan_Ait-Kaci, csma, Harold, IgorMozetic, Stella_Mitchell, ChrisW, PaulaP, Gary_Hallmark, Sandro, AxelPolleres, Mark_Proctor, 17:32:40 ... MichaelKifer, LeoraM 17:32:42 rrsagent, make minutes 17:32:42 I have made the request to generate http://www.w3.org/2007/12/18-rif-minutes.html ChrisW 17:32:44 for a crude 3valued logics for errors for filters... look at the sparql spec ;-) good bye. 17:32:50 rrsagent, make minutes 17:32:50 I have made the request to generate http://www.w3.org/2007/12/18-rif-minutes.html csma 17:32:51 it's not so bad, btw. 17:32:56 bye now! 17:32:57 -LeoraM 17:33:09 -AxelPolleres 17:33:13 Regrets: JosDeBruijn PaulVincent 17:33:21 rrsagent, make minutes 17:33:21 I have made the request to generate http://www.w3.org/2007/12/18-rif-minutes.html ChrisW 17:34:01 zakim, who is on the phone? 17:34:01 On the phone I see Hassan_Ait-Kaci, csma, ChrisW, Sandro, Mark_Proctor 17:34:12 scribenick: hassan 17:34:20 sorry - personal phone call. 17:34:24 rrsagent, make minutes 17:34:24 I have made the request to generate http://www.w3.org/2007/12/18-rif-minutes.html csma 17:35:08 -Hassan_Ait-Kaci 17:35:23 zakim, drop Mark_Proctor 17:35:23 Mark_Proctor is being disconnected 17:35:24 -Mark_Proctor 17:35:32 hmm I just got cutt off 17:35:42 telecon is over 17:35:51 ok 17:35:54 sandro, can you join for a sec 17:36:09 heh, we still didn't get to discuss uniterm for slotted representations 17:36:17 no :-( 17:36:25 btw, do you want them or not? 17:36:38 well they are needed for production rules 17:36:52 can you past a use case on the mailing list? 17:37:00 but over all I think its necessary, not just for production rules, to have anonymous slotted notation 17:37:06 frames insist that it has a url 17:37:09 which isn't always the case 17:37:20 anyway we can discuss this in another call 17:40:20 -ChrisW 17:40:23 -csma 17:44:28 -Sandro 17:44:30 SW_RIF()11:00AM has ended 17:44:31 Attendees were Hassan_Ait-Kaci, csma, Harold, IgorMozetic, Stella_Mitchell, ChrisW, PaulaP, Gary_Hallmark, Sandro, AxelPolleres, Mark_Proctor, MichaelKifer, LeoraM 17:45:02 @Mark, what do you mean, frame insist that it has an URL? The slot name? Not if it is rif:local, does it? 17:50:10 RRSAgent, pointer? 17:50:10 See http://www.w3.org/2007/12/18-rif-irc#T17-50-10 18:07:45 csma: to be honest I'm not an expert at the logic stuff 18:07:58 but it was something harold pointed me too and explained to me 18:08:26 as it seems frames have no mechanism to be anonymous 18:22:05 ok i'm outta here, I'll be on http://irc.codehaus.org #drools if anyone needs me 18:51:34 csma has left #rif