IRC log of owl on 2008-12-11

Timestamps are in UTC.

17:01:38 [RRSAgent]
RRSAgent has joined #owl
17:01:38 [RRSAgent]
logging to http://www.w3.org/2008/12/11-owl-irc
17:01:50 [sandro]
RRSAgent, make log public
17:02:05 [StellaMitchell]
StellaMitchell has joined #owl
17:02:09 [Zakim]
+ +039047101aaaa
17:02:21 [Zakim]
+Zhe
17:02:52 [Zakim]
+[IBM]
17:02:55 [StellaMitchell]
zakim, ibm is temporarily me
17:02:55 [Zakim]
+StellaMitchell; got it
17:03:01 [Zakim]
+ +1.845.227.aabb
17:03:02 [Zhe]
Zhe has joined #owl
17:03:14 [sandro]
zakim, who is here?
17:03:14 [Zakim]
On the phone I see bmotik (muted), Sandro, Ivan, josb, Zhe, StellaMitchell, +1.845.227.aabb
17:03:16 [ChrisW]
zakim, aabb is me
17:03:17 [Zakim]
On IRC I see Zhe, StellaMitchell, RRSAgent, ChrisW, josb, Zakim, ivan, bmotik, sandro, pfps, trackbot
17:03:17 [StellaMitchell]
i'll scribe
17:03:19 [Zakim]
+ChrisW; got it
17:03:31 [sandro]
scribe: StellaMitchell
17:04:08 [sandro]
zakim, who is on the phone?
17:04:08 [Zakim]
On the phone I see bmotik (muted), Sandro, Ivan, josb, Zhe, StellaMitchell, ChrisW
17:04:30 [bmotik]
Zakim, unmute me
17:04:30 [Zakim]
bmotik should no longer be muted
17:04:41 [bmotik]
Zakim, mute me
17:04:41 [Zakim]
bmotik should now be muted
17:04:54 [Zakim]
+??P7
17:04:55 [ivan]
:-(
17:05:20 [ivan]
zakim, drop me
17:05:20 [Zakim]
Ivan is being disconnected
17:05:21 [Zakim]
-Ivan
17:05:38 [sandro]
zakim, who is here?
17:05:38 [christine]
christine has joined #owl
17:05:38 [Zakim]
On the phone I see bmotik (muted), Sandro, josb, Zhe, StellaMitchell, ChrisW, ??P7
17:05:41 [DaveReynolds]
DaveReynolds has joined #owl
17:05:41 [Zakim]
On IRC I see christine, Zhe, StellaMitchell, RRSAgent, ChrisW, josb, Zakim, ivan, bmotik, sandro, pfps, trackbot
17:05:48 [ivan]
zakim, dial ivan-voip
17:05:48 [Zakim]
ok, ivan; the call is being made
17:05:50 [Zakim]
+Ivan
17:05:51 [sandro]
zakim, ??P7 is Christine
17:05:51 [Zakim]
+Christine; got it
17:06:19 [sandro]
agenda: http://lists.w3.org/Archives/Public/public-owl-wg/2008Dec/0035.html
17:06:37 [Zakim]
+??P8
17:07:09 [StellaMitchell]
sandro: Goal this meeting is to figure out the tasks and who will do them, but not to dig completely into all the technical details
17:08:06 [StellaMitchell]
sandro: four topics of coordination, the first is probably simple
17:08:19 [StellaMitchell]
...first item: rdf:text
17:08:29 [ChrisW]
Topic: rdf:text
17:08:43 [ChrisW]
zakim, list agenda
17:08:43 [Zakim]
I see nothing on the agenda
17:08:50 [ChrisW]
agenda+ rdf:text
17:08:53 [StellaMitchell]
...when it was published I said public comments should go to the public owl list
17:08:55 [ChrisW]
take up item 1
17:09:03 [ChrisW]
zakim, take up item 1
17:09:03 [Zakim]
agendum 1. "rdf:text" taken up [from ChrisW]
17:09:09 [sandro]
q?
17:09:34 [ChrisW]
agenda+ RIF OWL&RDF compatibility
17:09:57 [ChrisW]
agenda+ The list of datatypes
17:10:10 [ChrisW]
agenda+ OWL RL
17:10:14 [StellaMitchell]
chris: ask editors of rdf:text if they are willing to be the coordinators of public comments
17:10:49 [bmotik]
q+
17:10:57 [bmotik]
Zakim, unmute me
17:10:57 [Zakim]
bmotik should no longer be muted
17:11:00 [sandro]
ack bmotik
17:11:07 [StellaMitchell]
sandro: in terms of last call and dependences, the OWL ? spec depends on this, and some RIF documents will also be dependent also
17:11:34 [DaveReynolds]
q+
17:11:39 [sandro]
ack DaveReynolds
17:12:20 [StellaMitchell]
boris: is it ok to say in the spec that we sppport the rdf:text datatype, and if it changes later that will be ok
17:13:28 [StellaMitchell]
...use it in an opaque way, and so remove the dependency on the document. This applies to other datatype also.
17:13:33 [ivan]
q+
17:14:05 [StellaMitchell]
daver: rdf:text is a different case from other datatypes
17:14:30 [StellaMitchell]
boris: when you say you change rdf:text, you are not chaning the satisfiability of any document
17:14:38 [StellaMitchell]
daver: yes, it would be an observable change
17:14:50 [sandro]
ack ivan
17:14:51 [StellaMitchell]
....,Andy Seaborne sent an email about this
17:15:26 [StellaMitchell]
ivan: I don't see the problem
17:16:03 [StellaMitchell]
sandro: Andy's email sent to the public rdf:text list shows the problem
17:17:47 [StellaMitchell]
sandro: we need to make sure now that rdf:text will be defined in an acceptable way - we can't assume it will happen in the future
17:18:00 [sandro]
sandro; we need rdf:text to get to rec before anything that depends on it
17:18:10 [DaveReynolds]
Andy's message: http://lists.w3.org/Archives/Public/public-rdf-text/2008OctDec/0032.html
17:18:25 [sandro]
http://lists.w3.org/Archives/Public/public-rif-wg/2008Dec/0046.html
17:18:29 [StellaMitchell]
zakim, next item
17:18:29 [Zakim]
agendum 2. "RIF OWL&RDF compatibility" taken up [from ChrisW]
17:18:55 [StellaMitchell]
jos: summarizing the above email
17:21:14 [StellaMitchell]
...I made 5 proposals (labelled P1 through P5) in the email
17:21:54 [StellaMitchell]
sandro: I don't understand the relationship between owl 1 full and owl 2 full
17:22:25 [StellaMitchell]
sandro: I tentatively agree to proposal P1
17:22:51 [StellaMitchell]
chris: there was a change to OWL full in OWL2, but do we believe it to be insignificant?
17:23:08 [DaveReynolds]
Similarly I see no problem with P1
17:23:19 [sandro]
sandro: sounds like P1 is fine
17:23:26 [StellaMitchell]
jos, ivan: yes
17:23:44 [ivan]
s/ivan/boris/
17:24:18 [sandro]
q?
17:24:59 [StellaMitchell]
jos: summarized P2 and P3
17:25:39 [sandro]
sandro: In OWL 2 you can't signal that you're not in OWL 1, so year, P2 and P3 make sense.
17:25:41 [StellaMitchell]
sandro: as I understand, you are not allowed to signal whether you're in OWL 1 and OWL 2
17:25:53 [StellaMitchell]
boris: P2 and P3 are ok with me'
17:26:51 [sandro]
http://www.w3.org/2005/rules/wiki/SWC#Importing_RDF_and_OWL_in_RIF
17:27:46 [StellaMitchell]
jos: explaining IRIs of profiles. reference above.
17:27:56 [StellaMitchell]
sandro: note that these are not like OWL profiles
17:28:25 [StellaMitchell]
jos: does anyone disagree with P4?
17:28:38 [sandro]
Jos: drop OWL Dl annotaiton
17:28:39 [StellaMitchell]
sandro: do we still need the annotation profile?
17:28:47 [StellaMitchell]
jos: no, would drop it.
17:29:40 [StellaMitchell]
sandro: conformance clause for owl says everyone has to implement rdf serializaiton for owl and them may implement the other ones
17:29:53 [StellaMitchell]
s/them/they/
17:30:19 [sandro]
sandro: I think leave it RDF/XML, but maybe add a note about other syntaxes.
17:30:58 [StellaMitchell]
jos: I don't have a strong opinion about allowing other syntaxes to be imported
17:31:08 [StellaMitchell]
jos: summarizing P5
17:32:25 [StellaMitchell]
boris: what is meant by a combination?
17:32:28 [DaveReynolds]
Agree with P5 too
17:32:33 [sandro]
P5 sounds good...
17:32:55 [StellaMitchell]
jos: (explained combination)
17:33:06 [StellaMitchell]
chris: why should DLP be dropped?
17:33:25 [StellaMitchell]
jos: OWL 2 RL is sort of the same thing
17:34:27 [StellaMitchell]
chris: but is not the same thing, so why should we drop DLP? Most OWL implementations are currently OWL 1
17:35:50 [StellaMitchell]
jos: I made up this DLP, it's not the one you are thinking of that people have implemented
17:35:54 [sandro]
jos: no datatype support in Horrocks et al DLP. that's one of several differences.
17:36:53 [Zhe]
q+
17:36:59 [DaveReynolds]
+1 with Jos
17:37:04 [ivan]
+1 with Jos
17:37:32 [StellaMitchell]
chris: I'm not sure about dropping the DLP section from RIF, RDF and OWL compatibility document, I need to think about it more
17:37:37 [sandro]
ack Zakim
17:37:41 [sandro]
ack Zhe
17:38:35 [StellaMitchell]
zhe: when I started in the OWL WG, we had a DLP but the working group decided to drop it, and then later OWL 2 RL was defined, so I support dropping DLP
17:38:49 [StellaMitchell]
sandro: we'll investigate before deciding
17:39:18 [sandro]
topic: 3. The list of datatypes (aside from RL) (10 minutes)
17:39:30 [sandro]
http://www.w3.org/2005/rules/wiki/DTB#Symbol_Spaces
17:39:30 [sandro]
http://www.w3.org/2007/OWL/wiki/Syntax#Datatype_Maps
17:39:40 [StellaMitchell]
zakim, next item
17:39:40 [Zakim]
agendum 3. "The list of datatypes" taken up [from ChrisW]
17:40:20 [bmotik]
q+
17:40:39 [sandro]
ack bmotik
17:40:46 [StellaMitchell]
chris: we should coordinate on the set of datatypes, there is no real rationale for having different sets in RIF and OWL
17:40:48 [DaveReynolds]
http://www.w3.org/2005/rules/wiki/OWLRL#Datatypes_supported
17:41:30 [StellaMitchell]
boris: it's not just the list of types, but we have adapted the semantics of some of the datatypes, e.g. for double
17:42:35 [StellaMitchell]
sandro: from what I understand, the same reasons should apply to RIF, and RIF should use the same definitions
17:42:43 [sandro]
sandro: It sounds like there's nothing OWL specific here.... so RIF should also use owl:real, etc?
17:42:59 [StellaMitchell]
boris: RIF has casts between datatypes, and OWL does not
17:44:32 [sandro]
boris: imagine weight has range integer, and then someone gives a value of "70"^^xs:double --- that's inconsistent.
17:44:56 [StellaMitchell]
boris: giving example of how casts could results in inconsistency: range of certain property is integer, weight, someone puts 70.0 as double so
17:45:00 [sandro]
boris: In RIF you can do a cast, which allows you to hack around this situation.
17:45:44 [StellaMitchell]
boris: OWL doesn't support any functions
17:45:48 [DaveReynolds]
q+
17:46:33 [StellaMitchell]
chris: so we could adopt a common set of datatypes, where OWL doesn't include the built-ins and RIF does
17:47:17 [sandro]
ack DaveReynolds
17:47:45 [StellaMitchell]
dave: are you saying that owl real isn't separated from the integers?
17:48:06 [sandro]
boris explains owl:real and owl:realPlus
17:48:08 [StellaMitchell]
boris: owl real is the umbrella for all the numeric datatypes
17:49:07 [StellaMitchell]
chris: I'm trying to understand if there needs to be an actual difference in the set of datatypes
17:49:24 [StellaMitchell]
...such that we can share datatypes and RIF supports built-ins while OWL doesn't
17:49:44 [DaveReynolds]
dave: don't understand how "1.1"^^owl:real can be both a double and decimal, they are different
17:50:12 [StellaMitchell]
boris: with our datatype definitions, we are trying to be more user friendly
17:50:30 [StellaMitchell]
chris: so, owl:real is a superclass?
17:50:32 [StellaMitchell]
boris: yes
17:51:08 [StellaMitchell]
chris: ok, so there is a difference in some of the datatype definitions
17:51:54 [StellaMitchell]
chris: owl approach breaks xml schema compatibility
17:52:38 [StellaMitchell]
boris: we did talk to xml schema people and they weren't averse to this, and supported it
17:52:46 [Zhe]
sure
17:53:00 [sandro]
meeting extended until 20 after the hour.
17:53:16 [Zakim]
-Ivan
17:53:16 [StellaMitchell]
chris: so that feedback from xml schema group may help address the concerns of the production rule concerns in RIF
17:53:39 [ChrisW]
zakim, who is on the phone?
17:53:39 [Zakim]
On the phone I see bmotik, Sandro, josb, Zhe, StellaMitchell, ChrisW, Christine, DaveReynolds
17:54:42 [StellaMitchell]
jos: these issues with value spaces are subtle and I would be ok with changing to the way OWL is doing it, but I think the long list of datatypes is a problem
17:55:21 [StellaMitchell]
dave: owl:real sounds like a problem to me. people use decimal and double for specific reasons
17:55:37 [josb]
q+
17:55:56 [StellaMitchell]
dave: when you express something you need to know what it is
17:56:11 [christine]
christine has joined #owl
17:56:14 [StellaMitchell]
boris: you do always know what it is
17:57:25 [StellaMitchell]
...small problem might be when you say the range must be an integer and then put a double constant there that is actually an integer
17:57:33 [sandro]
boris: The only question is when you do class reasoning on types....
17:57:50 [StellaMitchell]
...in owl, we say you have not violated the range constraint in that case
17:57:59 [sandro]
sandro: in RIF this comes up with is-this-an-integer applied to "70"^^xs:float or "70"^^xs:decimal.
17:58:31 [StellaMitchell]
sandro: RIF needs a test case about this, to get feeback from the WG
17:58:59 [StellaMitchell]
jos: what sandro wrote above, in OWL would you interpret those as different objects?
17:59:12 [StellaMitchell]
boris: no, we interpret them all as the integer 70
17:59:52 [StellaMitchell]
...but 0.1 double is not the same as 0.1 decimal, because 0.1 double gets rounded
18:00:07 [sandro]
boris: "0.1"^^xs:float is NOT the same as "0.1"^^xs:decimal, because of rounding in the internal representation. We don't lose any precision.
18:00:47 [sandro]
boris "70"^^xs:float and "70"^^xs:decimal are IDENTICAL in OWL -- they are both the number 70.
18:01:40 [StellaMitchell]
boris: xml schema defines equality differently from identity
18:02:26 [StellaMitchell]
dave: if you put in value that is larger than the mantissa for xs:float, what happens?
18:03:07 [StellaMitchell]
boris: it would follow the mapping giving in xml schema, I don't know what it is off the top of my head
18:04:34 [ChrisW]
is 100000000000045 (assuming that is beyond the range of float) a *float*
18:04:47 [sandro]
boris: This gets messy, comparing doubles with integers, etc, but we did manage to implement this in Hermit.
18:06:03 [StellaMitchell]
chris: question - is the number above considered a float?
18:06:11 [DaveReynolds]
The test case is whether "100000000000045 "^^xsd:float = "100000000000045"^^xsd:integer, the answer should be no.
18:06:28 [StellaMitchell]
boris: yes, it is. but it might get rounded into another float
18:06:45 [Zhe]
or "1.0000000000000001"^^float = "1"^^integer, answer is yes
18:07:20 [sandro]
topic: 4. OWL RL (20 minutes)
18:08:33 [StellaMitchell]
sandro: summarize items from agenda
18:08:41 [sandro]
-- aligning the list of datatypes
18:08:41 [sandro]
-- providing the rules as a RIF Core document
18:08:41 [sandro]
-- any issues with the ruleset itself
18:08:41 [sandro]
-- rules/code to check the ontology
18:09:37 [StellaMitchell]
sandro: first item: since datatypes don't align, we couldn't express OWL RL in RIF
18:09:59 [StellaMitchell]
s/sandro:/dave:/
18:10:18 [sandro]
DaveReynolds: it would be ideal if the OWL-RL datatypes were the intersection of OWL and RIF-Core datatypes.
18:11:03 [StellaMitchell]
sandro: it will be easier to reduce the list of datatypes in OWL-RL than in the other OWL profiles
18:12:11 [StellaMitchell]
sandro: customers would want RIF and OWL to be aligned
18:12:20 [StellaMitchell]
dave: normalized strings
18:12:26 [josb]
q+
18:12:34 [sandro]
ack josb
18:13:00 [StellaMitchell]
jos: why in OWL-RL can you not allow datatypes with finite value spaces
18:13:22 [StellaMitchell]
boris: (missed answer)
18:14:00 [StellaMitchell]
...maybe in OWL-RL that restriction is not necessary
18:14:10 [StellaMitchell]
...we do in EL and QL
18:14:13 [sandro]
boris: Ah, the finiteness restriction on OWL-RL might not be necessary.
18:15:22 [StellaMitchell]
sandro: Dave, are you willing to see if we can get these extra datatypes added to RIF Core?
18:15:49 [StellaMitchell]
dave: I think it will be mostly up to Axel - I see no value in having things like ncname
18:16:14 [StellaMitchell]
boris: we kept it for consistency, so we didn't have to explain why we excluded it
18:16:32 [StellaMitchell]
dave: RIF took opposite approach: each inclusion had to be justified
18:19:16 [StellaMitchell]
jos: owl:rational would be something completely new for RIF
18:19:52 [sandro]
sandro: lets have RIF look at the RL datatype list and push back where necessary.
18:19:56 [StellaMitchell]
sandro: RIF needs to look at list of OWL datatypes and see which ones can go in RIF core and then ask OWL to remove the other ones
18:20:16 [StellaMitchell]
chris: does OWL 2 support all the RIF datatypes?
18:20:47 [StellaMitchell]
boris: there are 2 xquery, duration related ones that we don't support
18:21:58 [sandro]
DaveReynolds: I'm fine with my document being folded into Jos'
18:22:10 [StellaMitchell]
sandro: We need to decide what to do with the "OWL 2 RL in RIF" document
18:22:22 [josb]
q+
18:23:12 [StellaMitchell]
chris: in Dave's document there is the RIF core rule implementation of OWL 2 RL and there is a lot of background information. How about just taking the RIF Core implementation and making that the OWL RL profile?
18:23:45 [sandro]
bmotik: We're perfectly aware that a naive implementation of the OWL RL rules will have poor performance. But we wanted the semantics to be very clear.
18:24:16 [sandro]
bmotik: eg quadratic number of literals, but you'd need builtins and NAF, etc.
18:24:25 [sandro]
bmotik: and we didnt want to go there.
18:25:05 [StellaMitchell]
chris: I don't understand your point. I'm suggesting you express the ruleset in RIF Core syntax.
18:25:18 [sandro]
chrisw: How about using RIF Core Presentation Syntax to express the OWL-RL rules?
18:25:24 [StellaMitchell]
boris: ok, I understand the question. I'm not sure right now, have to consult with others.
18:25:25 [Zhe]
q+
18:26:35 [StellaMitchell]
chris: I think if we solve the datatype issues, then I think it would just be a small change to the syntax
18:27:38 [sandro]
ack josb
18:27:59 [StellaMitchell]
dave: owl uses ellipsis, makes it easier to read, less explicity about what to implement
18:28:41 [sandro]
jos: my embedding stuff does not operate on T(s,p,o) but on translation to RIF. very different.
18:28:50 [sandro]
ack Zhe
18:29:35 [sandro]
Zhe: I don't want to take out the RDF-oriented rule in the OWL-RL spec, but I like adding RIF stuff.
18:30:29 [StellaMitchell]
boris: my personal opinion is that changing the actual ruleset would be painful for OWL
18:30:40 [StellaMitchell]
...and require extensive negotiations
18:30:48 [StellaMitchell]
...but changing syntax may be ok
18:31:02 [ChrisW]
"Life IS pain, princess. Anyone who says otherwise is selling something" - Princess Bride
18:31:14 [DaveReynolds]
:-)
18:31:39 [Zhe]
thanks
18:31:47 [Zakim]
-Zhe
18:31:48 [Zakim]
-bmotik
18:31:49 [Zakim]
-DaveReynolds
18:31:49 [Zakim]
-StellaMitchell
18:31:50 [christine]
bye
18:31:51 [Zakim]
-ChrisW
18:31:51 [Zakim]
-Sandro
18:31:53 [Zakim]
-josb
18:31:57 [ChrisW]
rrsagent, make minutes
18:31:57 [RRSAgent]
I have made the request to generate http://www.w3.org/2008/12/11-owl-minutes.html ChrisW
18:31:58 [Zakim]
-Christine
18:31:59 [Zakim]
Team_(owl)17:00Z has ended
18:31:59 [sandro]
StellaMitchell, thanks so much for scribing.
18:32:00 [Zakim]
Attendees were Sandro, bmotik, Ivan, +039047101aaaa, josb, Zhe, StellaMitchell, +1.845.227.aabb, ChrisW, Christine, DaveReynolds
18:32:16 [ChrisW]
rrsagent, make logs public
18:32:17 [StellaMitchell]
you're welcome
18:32:25 [ChrisW]
+1 thanks
18:32:30 [ChrisW]
rrsagent, make minutes
18:32:30 [RRSAgent]
I have made the request to generate http://www.w3.org/2008/12/11-owl-minutes.html ChrisW
18:33:19 [StellaMitchell]
thanks, I have the minutes