17:58:44 <RRSAgent> RRSAgent has joined #shapes
17:58:44 <RRSAgent> logging to http://www.w3.org/2016/04/07-shapes-irc
17:58:46 <trackbot> RRSAgent, make logs rdf-data-shapes
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17:58:48 <trackbot> Zakim, this will be SHAPES
17:58:48 <Zakim> ok, trackbot
17:58:49 <trackbot> Meeting: RDF Data Shapes Working Group Teleconference
17:58:49 <trackbot> Date: 07 April 2016
17:59:29 <simonstey> simonstey has joined #shapes
17:59:43 <Arnaud> present+
17:59:54 <Arnaud> agenda: https://www.w3.org/2014/data-shapes/wiki/Meetings:Telecon2016.04.07
17:59:59 <Arnaud> chair: Arnaud
18:00:00 <simonstey> present+
18:00:00 <markh> markh has joined #shapes
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18:01:35 <hknublau> present+
18:02:35 <Dimitris> present+
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18:04:04 <hsolbrig> present+ hsolbrig
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18:05:45 <Labra> * I am trying to connect through webex but something different occurs...it is asking by room ID?
18:06:13 <Arnaud> 646 464 360
18:06:20 <Arnaud> it's on the agenda
18:06:47 <Arnaud> I don't know why it has become like that, we have to go through that step every time now
18:07:53 <Labra> * password?
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18:09:05 <pfps> present+
18:11:05 <Labra> Now I can hear
18:11:13 <Labra> if you want to scribe, I can do
18:11:21 <Labra> but no talking on my side :)
<Labra> topic: Admin
18:11:47 <Arnaud> PROPOSED: Approve minutes of the 31 March 2016 Telecon: http://www.w3.org/2016/03/31-shapes-minutes.html
18:11:52 <Arnaud> scribe: labra
18:11:52 <pfps> looked ok
18:12:02 <Arnaud> RESOLVED: Approve minutes of the 31 March 2016 Telecon: http://www.w3.org/2016/03/31-shapes-minutes.html
18:12:44 <Labra> Arnaud: Several issues are in the agenda...some of them can be later
18:12:57 <pfps> i think that it would be worthwhile to discuss 134 today.
18:13:01 <Labra> ...some of them through the mailing list
<Labra> topic: ISSUE-80: Scheme URIs
18:13:58 <Arnaud> PROPOSED: Close ISSUE-80, adding sh:stem to the spec outlined in Eric's email https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Mar/0311.html
18:14:09 <ericP> +1
18:14:16 <simonstey> +0
18:14:17 <Labra> +1
18:14:22 <pfps> 0
18:14:23 <kcoyle> +1
18:14:24 <hsolbrig> +0
18:14:27 <Dimitris> 0
18:14:48 <jamsden> 0
18:15:09 <hknublau> 0
18:15:31 <Arnaud> RESOLVED: Close ISSUE-80, adding sh:stem to the spec outlined in Eric's email https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Mar/0311.html
<Labra> topic: ISSUE-78: sh:abstract
18:16:15 <Labra> Arnaud: Next issue sh:abstract seems not to be relevant any longer
18:16:47 <Labra> ...we wanted to close it some time ago
18:17:06 <Arnaud> PROPOSED: Close ISSUE-78, without adding sh:abstract, given that sh:ShapeClass was dropped
18:18:04 <simonstey> +q
18:18:17 <Labra> Arnaud: there is a tension between how much SHACL should be a data modeling language
18:18:43 <Labra> ...the groups is mainly against that, after a long discussion there was some compromise
18:19:10 <simonstey> -q
18:19:11 <Labra> Hsolbrig: Let's say we define a class and it has several subclasses...
18:19:32 <Labra> ...and I want to specify that it is abstract so there is no instance of it
18:19:45 <Arnaud> issue-78
18:19:45 <trackbot> issue-78 -- Should SHACL support marking classes as abstract -- open
18:19:45 <trackbot> http://www.w3.org/2014/data-shapes/track/issues/78
18:19:46 <hknublau> q+
18:19:47 <Labra> ...for OSLC it means there is no creation dialog
18:19:51 <Arnaud> ack hknublau
18:20:07 <Labra> Holger: that's exactly the use case that we have
18:20:49 <Labra> ...with the redefinition of the metamodel it is no longer needed...
18:21:02 <Labra> ...but we have used it
18:21:06 <jamsden> q+
18:21:11 <Arnaud> ack jamsden
18:21:15 <Labra> ...we could use it in another namespace and don't worry about shacl
18:21:37 <Labra> jamsden: the argument is that we don't need that particular constraint
18:22:45 <Labra> ...it is a useful property to have and a very common thing to do when defining vocabularies
18:23:03 <Labra> ...I would not be in favour of dropping it
18:23:06 <ericP> q+ to describe uses of "abstract"
18:23:10 <simonstey> +q
18:23:14 <Arnaud> ack ericP
18:23:14 <Zakim> ericP, you wanted to describe uses of "abstract"
18:24:11 <kcoyle> I don't find a use case that matches this
18:24:15 <Labra> ericP: the use case was I want to have a notion of hierarchy and there was a semantics of abstract
18:24:35 <Labra> ...but my understanding is that we are not there yet...we don't have the notion of subshapes
18:24:42 <Arnaud> ack simonstey
18:24:43 <Labra> ...and how to derive shapes
18:25:38 <Labra> simonstey: would like to ask if there are other constraints that apply to nodeConstraint
18:26:36 <Labra> Arnaud: I don't feel confortable to close it dropping because it seems there are people who see it useful
18:26:40 <hknublau> @simonstey sh:closed is also used as NodeConstraint only
18:26:47 <Arnaud> https://www.w3.org/2014/data-shapes/wiki/Proposals#ISSUE-78:_Abstract_Classes
18:26:51 <Labra> ...there is a link to the proposal page with some discussion a while ago
18:27:14 <Labra> ...Peter's objection was that it was not well defined
18:27:25 <Labra> ...those who care should improve the proposal
18:27:47 <Labra> pfps: I objected because if was not well enough defined
18:27:53 <hknublau> Any SHACL feature that is removed from core can be covered by extension vocabularies.
18:28:09 <simonstey> +q
18:28:12 <kcoyle> q+
18:28:39 <Arnaud> ack simonstey
18:28:56 <Labra> simonstey: maybe the problem is the name
18:29:14 <Labra> ...sh:abstract seem to have a problem and we could it call differently
18:29:44 <Labra> ...we are not modelling something, if we define a node constraint with sh:abstract = true we just want to say that this class has no instances...
18:29:55 <Arnaud> ack kcoyle
18:29:58 <Labra> ...in the end, maybe, it's just the naming
18:30:15 <Labra> kcoyle: can this be handled with the cardinality constraints?
18:30:54 <Labra> we could do it constraining the cardinality of rdf:type
18:30:59 <hknublau> It interacts with inferencing (or not), so this is a slippery slope.
18:31:45 <Labra> ericP: not really, we could have student, teacher that derive from person
18:32:33 <Labra> ...some explanation
18:32:51 <Labra> Arnaud: is there any one who wants to try a better proposal?
18:33:04 <jamsden> I'll give it a try
18:33:18 <Labra> Holger: My other proposal was to define the property without semantics and just as an annotation
18:33:45 <Labra> ...it's just as sh:name
18:33:47 <simonstey> +q
18:33:57 <Arnaud> ack simonstey
18:33:57 <Labra> ...it doesn't lead to validation errors
18:34:22 <Labra> simonstey: the danger of defining just as an annotation is that it goes more as a modelling construct
18:34:56 <Labra> ...there may be some conflicts with a modeling language
18:35:23 <pfps> q+
18:36:04 <Labra> pfps: there may be several problems with it
18:36:07 <Arnaud> ack pfps
18:36:18 <pfps> OK
<Labra> topic: ISSUE-136: Property pair names
18:36:38 <Arnaud> PROPOSED: Close ISSUE-136, renaming sh:equals, sh:notEquals,  sh:lessThan, sh:lessThanOrEquals to sh:equalProperty,  sh:notEqualProperty, sh:lessThanProperty, sh:lessThanOrEqualProperty  respectively
18:36:51 <simonstey> +q
18:37:01 <hknublau> +1
18:37:02 <Arnaud> ack simonstey
18:37:30 <Labra> simonstey: What's a lessthatProperty?
18:37:31 <TallTed> equalValue makes much more sense to me than equalProperty
18:37:56 <kcoyle> TT - I, too, suggested equalValue
18:38:00 <Labra> s/lessthatProperty/lessThanProperty/
18:38:29 <TallTed> or valueEqual, valueLessThan ... or propertyValueEqual, propertyValueLessThan?
18:38:56 <Labra> Holger: one problem with lessThan leaving lessThanProperty
18:39:10 <Labra> ...I also like disjoint
18:39:12 <TallTed> Bob, Jim, Fred!
18:39:23 <Labra> Arnaud: problem with names
18:39:40 <Labra> ...who cares to give a proposal?
18:39:57 <kcoyle> q+
18:40:00 <Arnaud> ack kcoyle
18:40:03 <hknublau> PROPOSED: sh:equalPropertyValues, sh:disjointPropertyValues, sh:lessThanPropertyValues, sh:lessThanOrEqualsPropertyValues
18:40:28 <Dimitris> values or value?
18:40:30 <Labra> kcoyle: Ted and I have the feeling that having the word value
18:40:36 <Labra> ...is better
18:41:08 <pfps> q+
18:41:24 <Labra> Holger: it is important to include property
18:41:30 <Arnaud> ack pfps
18:41:41 <ericP> you need a "*" operator for dereferencing
18:41:46 <Labra> pfps: we are seing another problem with the general syntax of SHACL
18:42:02 <Labra> ...the division of propertyConstraint, nodeConstraint and inverse...
18:42:12 <Labra> ...there is very few intuition...
18:42:32 <Labra> ...it doesn't matter, it will still be horrible
18:42:45 <jamsden> q+
18:42:51 <Arnaud> ack jamsden
18:43:04 <Labra> jamsden: I agree with all of the above
18:43:12 <TallTed> q+
18:43:55 <Arnaud> ack TallTed
18:43:56 <Labra> ...I would rather use commonly used names rather than long a precise names
18:44:26 <Labra> TallTed: I am sympathetic to some of what Peter has already said
18:45:17 <Labra> ...we need clear names and labels for these things
18:46:15 <Labra> ...we may use opaque labels
18:46:43 <kcoyle> q+
18:46:52 <Arnaud> ack kcoyle
18:46:55 <pfps> I rather like sh:∅ as the replacement for sh:notEquals
18:46:55 <Dimitris> if we use PV as suffix? e.g. equalsPV
18:47:04 <hknublau> Please decide one way or another. I don't like the dragging on.
18:47:27 <Labra> kcoyle: we should try for shorter names
18:48:09 <Labra> Arnaud: the names as they are, are short
18:48:22 <Labra> ...maybe they are misleading, but people will learn
18:48:50 <pfps> sh:notEquals is not equal to the negative of sh:equals
18:48:53 <Labra> TallTed: do we need equal and notEqual when we already have not?
18:49:23 <pfps> sh:lt and sh:lte cannot be defined in terms of the other
18:50:47 <Labra> pfps: I proposed sh:notEquals to be sh:disjoint
18:50:57 <Arnaud> PROPOSED: Close ISSUE-136, keeping sh:equals, sh:lessThan, sh:lessThanOrEquals, changing sh:notEquals to sh:disjoint
18:51:06 <simonstey> +1
18:51:06 <hknublau> 0
18:51:15 <pfps> +1
18:51:21 <Labra> 0
18:51:24 <hsolbrig> 0
18:51:24 <TallTed> ...  sh:propertyValueEqual, sh:propertyValueDisjoint, sh:propertyValueLT, sh:propertyValueLTE, sh:propertyValueGT, sh:propertyValueGTE ...
18:51:31 <Dimitris> +.5
18:51:36 <pfps> sh:gt  can easily be defined in terms of sh:lt
18:51:49 <Dimitris> equalsWith / disjointWith?
18:52:06 <kcoyle> +.5
18:53:31 <jamsden> if equal means same literal or URI, then that seems pretty clear
18:53:58 <pfps> NO
18:54:08 <pfps> q+
18:54:13 <pfps> q-
18:54:25 <Arnaud> RESOLVED: Close ISSUE-136, keeping sh:equals, sh:lessThan, sh:lessThanOrEquals, changing sh:notEquals to sh:disjoint
<Labra> topic: ISSUE-96: Violation IDs
18:55:12 <Arnaud> issue-96
18:55:12 <trackbot> issue-96 -- Should the validation results contain stable IDs to indicate the type of violation -- open
18:55:12 <trackbot> http://www.w3.org/2014/data-shapes/track/issues/96
18:55:43 <Arnaud> PROPOSED: Close ISSUE-96, adding an ID to validation results for each constraint type. All open proposals include URIs for each constraint  component, and these align with the mechanism used by the extension  mechanism.
18:56:18 <Labra> Holger: all of the proposals have the notion or something comparable to constraint components (templates)
18:56:38 <Labra> ...each of those components can produce certain types of constraint violations
18:56:57 <Labra> ...for tools it would be good to know what kind of violation result it i
18:57:08 <Labra> ...if we use strings it is not ok
18:57:27 <pfps> q+
18:57:33 <Labra> ...as long as we agree that it should be done, then it is a matter to naming
18:57:43 <jamsden> could those URIs be enumeration literals (instances) of some error class
18:57:48 <Arnaud> ack pfps
18:57:57 <Labra> pfps: the results are too complex
18:58:05 <Labra> ...this is also unnecessary
18:58:33 <Labra> ...validation reports already point to the souce constraint, shape and template
18:58:43 <Labra> ...why should we add something else?
18:59:51 <Labra> Holger: there is sourceConstraint which is responsible for the error
18:59:56 <Arnaud> PROPOSED: Close ISSUE-96, sh:sourceConstraint fulfill this needs
19:00:23 <simonstey> +1
19:00:33 <pfps> +1
19:00:56 <kcoyle> +0
19:01:14 <Arnaud> s/sh:sourceConstraint/sh:sourceTemplate/
19:01:18 <pfps> +1
19:01:21 <hsolbrig> 0
19:01:24 <jamsden> +1
19:01:24 <hknublau> +1
19:01:25 <Dimitris> +1
19:01:27 <TallTed> +1
19:01:28 <Labra> 0
19:01:50 <Arnaud> RESOLVED: Close ISSUE-96, sh:sourceTemplate fulfills this needs
19:03:19 <Labra> topic: ISSUE-134: knowing inverse
19:03:19 <trackbot> issue-134 -- does SHACL syntax distinguish inverse property constraints -- open
19:03:19 <trackbot> http://www.w3.org/2014/data-shapes/track/issues/134
19:03:45 <pfps> q+
19:03:52 <Arnaud> ack pfps
19:04:23 <Labra> pfps: we are in a situation were figuring out where a shapes graph is ok
19:04:24 <Arnaud> https://lists.w3.org/Archives/Public/public-data-shapes-wg/2016Apr/0021.html
19:04:49 <Labra> ...in the normal case, it looks easy, but there may be several places that we should nail down in the spec
19:04:57 <Labra> ...to define what is a valid shacl document
19:05:12 <Labra> ...there are several holes and patches and more holes...
19:05:33 <Labra> ...in my recent email there are several cases where it is not clear what the answer is
19:06:40 <Labra> Arnaud: how do we deal with invalid graphs?
19:07:17 <Labra> ...Holger said if it is invalid, let the implementation do what it wants...but there are more options...
19:08:07 <hknublau> For the record, I do not prefer the option to not define what happens. I just enumerated this as one option, if we don't have enough time in the WG.
19:08:14 <Labra> ...it is fairly common to think what happens when the input is valid, but trying to know what happens when the input isn't is usually very hard
19:08:25 <Labra> ...in HTML it happened in HTML5
19:08:44 <Labra> ...because the web is full of broken HTML
19:08:56 <Labra> ...the XML Schema group there is a strict/lax mode
19:09:12 <Labra> ...this may be a compromise
19:09:45 <Labra> ...if we are in strict mode then the implementation stop and complains while in lax mode, it can do other things...
19:10:08 <hknublau> q+
19:10:10 <Labra> ...I agree that the spec needs to address the corner cases
19:10:13 <Arnaud> ack hknublau
19:10:31 <Labra> Holger: in the past we talked about creating a shapes graph for shacl
19:10:59 <Labra> ...I am of the opinion that there are several cases where this syntax must be enforced
19:11:12 <Labra> ...some rules are very important while others are less important
19:11:46 <Labra> ...if we have time, let's do it
19:12:08 <Labra> ...the issue of not doing this is that there is a lot unspecified
19:12:19 <Dimitris> q+
19:12:23 <Arnaud> ack Dimitris
19:12:42 <Labra> Dimitris: the shapes graph can be a grammar for the language
19:12:48 <Labra> ...it can self-descriptive
19:13:03 <Arnaud> s/can/can be/
19:13:14 <Labra> ...we don't need to define the edge cases
19:13:35 <Labra> pfps: right now, it is not possible
19:13:58 <Labra> ...it may be a good idea, the problem is that you are saying that the language is...this program...
19:14:16 <Labra> ...I hope there should be other ways to describing the language
19:14:17 <Dimitris> q+
19:14:33 <Labra> ...I would say the first thing we have to is define what is in the language and what is not
19:14:50 <Arnaud> ack Dimitris
19:14:53 <Labra> ...first of all, we have to decide what is in the language
19:15:14 <Labra> Dimitris: we can define a set of basic shapes
19:15:31 <pfps> q+
19:15:40 <Arnaud> ack pfps
19:15:41 <Labra> * I lost part of what Dimitris said
19:16:22 <Labra> pfps: Depending on shacl to define the syntax of shacl is problematic
19:16:40 <Labra> ...we should have some clearly wording of what is a shacl graph and what is not
19:16:46 <Labra> ...we are not even there yer
19:16:53 <Labra> s/yer/yet/
19:17:11 <Labra> ...there should be a way to define what is a valid shapes graph and what is not
19:17:37 <Labra> ...in the current design of shacl there are more and more bits that are defy my intuition
19:18:06 <Labra> s/that are defy/that defy/
19:19:14 <hknublau> q+
19:19:21 <Labra> Arnaud: there seems to be a great problem with the syntax
19:19:24 <pfps> The situation is not as stark as that, I think.  The common situations should be OK and should work right.
19:19:42 <jamsden> q+
19:19:53 <Arnaud> ack hknublau
19:20:13 <Labra> hknublau: It is easy to criticise things, but it is difficult to fix them
19:20:36 <Labra> ...it is easy to give the impression that something is broken, but the language isn't broken
19:21:04 <Labra> ...what we should do is to go throught the issues and tickets
19:21:07 <Arnaud> ack jamsden
19:21:41 <Labra> jamsden: I would like to offer some help to solve the issue
19:22:11 <Labra> ...it seems the peter and holger have the knowledge to solve it, I wonder if it would make sense for them to have a face to face
19:22:15 <Labra> to solve those issues
19:22:51 <Labra> ...sometimes those face to face meetings are productive
19:22:53 <pfps> I'm confused.  What are the two conflictting approaches?
19:23:20 <Labra> hknublau: there are other people who have the background to help
19:23:22 <TallTed> q+
19:23:41 <Labra> ...I would like to have some task force to solve it outside of these time slots
19:24:08 <Labra> ...we are all in 3 different continents and it's hard to do a face 2 face
19:24:11 <pfps> q+
19:25:17 <Arnaud> ack TallTed
19:25:29 <Labra> Arnaud: I agree that it seems some of these needs more work and talking
19:25:47 <Labra> TallTed: It is true that our calls are shorts (although long)
19:26:35 <Labra> ...one of things to recognize is that we are different people with different styles
19:26:56 <Labra> ...peter's style is sometimes frustrating when he says is completely broken
19:27:27 <pfps> q-
19:28:17 <Labra> Arnaud: It might be worth to have some extra times
19:28:32 <Labra> ...maybe we should have a long call (2/3 hours) on one issue
19:28:53 <hknublau> sounds good
19:29:02 <Labra> ...maybe it is not necessary to have all the people, just the people interested
19:29:34 <Labra> pfps: we cannot go anywhere without solving the fundamental problems
19:30:15 <Labra> Arnaud: I would propose to have some time and do a poll to have some discussion
19:30:34 <TallTed> I wonder about more-and-more"fundamental problems" that are found on every read through
19:30:56 <Arnaud> trackbot, end meeting
19:30:56 <trackbot> Zakim, list attendees
19:30:56 <Zakim> As of this point the attendees have been Arnaud, simonstey, hknublau, Dimitris, hsolbrig, pfps, ericP, jamsden, labra, markh, kcoyle, TallTed
19:31:04 <trackbot> RRSAgent, please draft minutes
19:31:04 <RRSAgent> I have made the request to generate http://www.w3.org/2016/04/07-shapes-minutes.html trackbot
19:31:05 <trackbot> RRSAgent, bye
19:31:05 <RRSAgent> I see no action items