IRC log of rdf-star on 2024-04-12

Timestamps are in UTC.

14:06:31 [RRSAgent]
RRSAgent has joined #rdf-star
14:06:36 [RRSAgent]
logging to https://www.w3.org/2024/04/12-rdf-star-irc
14:06:41 [Zakim]
Zakim has joined #rdf-star
14:07:03 [TallTed]
TallTed has changed the topic to: RDF-star WG - Semantics Task Force - 2024-04-12 agenda: https://www.w3.org/events/meetings/6d0cd306-0be8-4267-865a-6272cc8d9da4/20240412T100000/
14:07:41 [TallTed]
meeting: RDF-star Semantics TF
14:07:43 [TallTed]
agenda: https://www.w3.org/events/meetings/6d0cd306-0be8-4267-865a-6272cc8d9da4/20240412T100000/
14:07:44 [agendabot]
TallTed, sorry, I did not recognize any agenda in https://www.w3.org/events/meetings/6d0cd306-0be8-4267-865a-6272cc8d9da4/20240412T100000/
14:07:45 [TallTed]
scribe: ?scribe?
14:07:47 [TallTed]
chair: ?chair?
14:07:49 [TallTed]
present+ souri, gkellogg, niklasl, TallTed, tl, AndyS, enrico, fsasaki
14:07:51 [TallTed]
topic: continuing discussion on how to constructively blend Amazon's concerns into the current structure of the RDF 1.2 proposal
14:09:19 [TallTed]
subtopic: many-to-many vs many-to-one reifiers-to-triple_terms
14:11:47 [TallTed]
RRSAgent, draft minutes
14:11:49 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
14:12:14 [enrico]
enrico has joined #rdf-star
14:12:18 [enrico]
present+
14:12:19 [TallTed]
previous meeting: https://www.w3.org/2024/04/11-rdf-star-minutes.html
14:12:19 [TallTed]
next meeting: https://www.w3.org/2024/04/18-rdf-star-minutes.html
14:12:24 [TallTed]
RRSAgent, draft minutes
14:12:26 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
14:12:34 [TallTed]
RRSAgent, make logs public
14:13:07 [Souri]
Souri has joined #rdf-star
14:13:16 [enrico]
q+
14:13:16 [TallTed]
regrets+ ora
14:13:16 [Souri]
present+
14:15:24 [Souri]
q+
14:16:17 [pchampin]
q+
14:16:29 [enrico]
ack enrico
14:16:34 [enrico]
ack souri
14:18:48 [enrico]
enrico: a solution is to have general well-formedness for many-to-many, and then various best practices: for LPGs, annotations, provenance, n-ary relations, events and situations, etc
14:19:20 [TallTed]
RRSAgent, draft minutes
14:19:21 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
14:19:42 [AndyS]
souri: suggests an "LPG profile"
14:20:17 [AndyS]
souri: (full) RDF 1.2 should be limited by LPG
14:20:27 [AndyS]
scribe: AndyS
14:20:29 [TallTed]
s/?scribe?/ad-hoc/
14:20:29 [TallTed]
scribe+ enrico, AndyS
14:20:35 [fsasaki]
q+
14:20:50 [TallTed]
RRSAgent, draft minutes
14:20:51 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
14:21:02 [AndyS]
souri: not everyone is interested in that restriction.
14:21:13 [enrico]
ack pchampin
14:21:28 [tl]
I understood that souri: (full) RDF 1.2 should NOT be limited by LPG
14:21:48 [AndyS]
pchampin: about undirected edges and the need for many-to-many
14:21:51 [TallTed]
s/scribe: ad-hoc//
14:21:51 [TallTed]
RRSAgent, draft minutes
14:21:52 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
14:22:24 [AndyS]
... there are other ways to model this e.g. subproperty, symmetric properties
14:22:51 [enrico]
enrico: LPG undirected edges need many-to-many: << :w1 | :liz :married :richard >> :location :las-vegas . << :w1 | :richard :married :liz >> :date 1966 .
14:23:05 [AndyS]
s/souri: (full) RDF 1.2 should be limited by LPG/souri: (full) RDF 1.2 should not be limited by LPG/
14:23:18 [niklasl]
q+
14:24:22 [TallTed]
RRSAgent, draft minutes
14:24:23 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
14:24:44 [AndyS]
q?
14:24:57 [enrico]
ack fsasaki
14:24:58 [AndyS]
ack fsasaki
14:25:26 [TallTed]
s/?chair?/ad-hoc/
14:25:34 [AndyS]
fsasaki: best practice for LPG encoding to give best interoperability - not part of SemTF
14:25:35 [tl]
q+
14:25:50 [AndyS]
... maybe main meeting and with LPG people
14:26:43 [AndyS]
niklasl?
14:28:12 [AndyS]
niklasl: my angle is to understand the problem with many-to-many (M2M) from an LPG POV.
14:29:02 [AndyS]
... if an edge in LPG is an instance of a relationship, (unclear to me) - no notion of denotes.
14:29:56 [AndyS]
... are we going overboard here? Entailment forces M2M
14:32:07 [AndyS]
... does M2M to confuse more than it helps? I don't think so.
14:33:23 [AndyS]
tl: sematics of multi-edge reification - is a foreach semantics or it applies to the collection.
14:34:22 [pchampin]
q+
14:34:57 [niklasl]
q-
14:35:15 [AndyS]
ack tl
14:35:43 [Souri]
Here is a source of confusion for me: I think rdf:reifies is multi-valued, but not set-valued. This is different than a named graph, which is an association of a resource with a set of triples.
14:36:22 [TallTed]
RRSAgent, draft minutes
14:36:23 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
14:36:29 [Souri]
q+
14:37:56 [fsasaki]
q+
14:38:22 [AndyS]
enrico: what is confusing here if others can use one reifier for multiple triples
14:38:44 [AndyS]
ack pchampin
14:38:52 [AndyS]
pchampin: I am neutral here.
14:39:44 [AndyS]
... I think that the confusing is how to explain (not the semantics) the rationale for the design - the intended meaning
14:39:52 [enrico]
q+
14:40:12 [AndyS]
... e:g: rdf:subject is different to rdf:object
14:40:39 [AndyS]
... not clear we have the same understanding of rdf:refiies
14:41:40 [TallTed]
s/refiies/reifies/
14:41:45 [AndyS]
... "intended meaning" is not captured by formal semantics
14:42:17 [AndyS]
... rdf:reifies -- what is the "intended meaning"?
14:42:51 [AndyS]
... don't know what the graphic is for the multi-triple case.
14:43:31 [pfps]
pfps has joined #rdf-star
14:43:36 [enrico]
ack souri
14:43:44 [pfps]
q+
14:43:44 [pfps]
present+
14:43:54 [fsasaki]
present+
14:44:28 [AndyS]
souri: hard to cast LPG in RDF language
14:45:54 [AndyS]
... I'm asking about multi valued rdf:reifies - multi-valued or container valued?
14:46:01 [tl]
q?
14:46:45 [pfps]
q+, to say that if there is no many-to-many reification then the many-to-many case looks exactly like the many-to-one case as far as users are concerned
14:47:49 [AndyS]
s/container valued/container-valued/
14:47:58 [tl]
if a person has hobbies tennis,swimming and skiing, those are three distinct hobbies, but they are also all all sports related hobbies. the distinction between multi-value and set doesn't make much sense to me. it depends on teh contents
14:49:35 [AndyS]
ask fsasaki
14:49:41 [fsasaki]
Citation from Rinke Hoeskstra, Elsevier, from LinkedIn: "Compatibility is essential, not just for querying across the graphs, but also for graph production pipelines where the wrangling of data happens in RDF and the serving happens in a PG projection. "
14:49:43 [AndyS]
ack fsasaki
14:49:52 [AndyS]
s/ask fsasaki//
14:51:51 [AndyS]
ack enrico
14:52:19 [AndyS]
enrico: the meaning of rdf:reifies will be in the best practices document.
14:53:00 [AndyS]
... let's wait for this document
14:53:17 [pchampin]
q+
14:53:31 [AndyS]
... several profiles for LPGs which will take sometime to develop
14:54:59 [AndyS]
ack pfps
14:56:13 [AndyS]
pfps: re: the neptune input. many-to-many looks like many-to-one - SPARQL Update is affected, nothing else.
14:56:15 [AndyS]
q+
14:56:33 [AndyS]
... not seeing users are hurt by M2M.
14:57:12 [AndyS]
ack pchampin
14:57:17 [pfps]
or even affected by many-to-many
14:57:54 [AndyS]
pchampin: M2M needs to represent the reification
15:00:46 [AndyS]
... "reificiation" is an abstract concept making it hard to understand and M2M adds to that
15:01:13 [pchampin]
q?
15:01:23 [pchampin]
scribe+
15:01:51 [pchampin]
AndyS: to pfps's remark that M2M looks like M2O, it is not as simple with SPARQL;
15:02:02 [pchampin]
... querying means closing the world.
15:02:13 [pchampin]
q?
15:02:18 [pchampin]
ack AndyS
15:02:20 [AndyS]
ack AndyS
15:03:19 [Souri]
q+
15:03:34 [pchampin]
niklasl: I expect the interpretation of an edge in LDP to be the relationship.
15:03:40 [AndyS]
niklasl: re: users of LPG -- the interpretation of the edge as nodes and edges.
15:03:47 [pchampin]
scribe-
15:04:09 [pchampin]
q+
15:06:41 [gkellogg]
scribe+
15:07:12 [AndyS]
scribe-
15:07:13 [pchampin]
ack Souri
15:07:40 [gkellogg]
Souri: is rdf:reifies multi-valued, or not.
15:07:43 [tl]
q+
15:07:59 [gkellogg]
... Is is multi-valued or set-valued?
15:08:41 [gkellogg]
... If you have the same reifier for multiple triples, we may want to add something that affects multiple triples.
15:09:12 [gkellogg]
... Once you've done that, you can't say thing about an individual triple now; you'd need to create a new reifier to connect only to one triple to say things about that.
15:09:58 [gkellogg]
... The ability to have multi-valued rdf:reifies gives the user to say things about multiple triple terms together with one annotation or set of annotations, while staying inside a single RDF named graph.
15:10:27 [gkellogg]
... That ability is not there today; you can create multiple graphs, but they're in different scopes; you're not able to take sub-groups of triples and annotate them.
15:10:40 [TallTed]
RRSAgent, draft minutes
15:10:41 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
15:10:52 [gkellogg]
... The ability to allow multi-valued rdf:reifies provides for different modeling opportunities.
15:11:08 [pchampin]
q?
15:11:12 [pchampin]
ack pchampin
15:11:36 [gkellogg]
pchampin: Responding to Souri, your question about set- vs multi-valued is important.
15:11:38 [TallTed]
i/regrets+ ora/present+ pchampin
15:11:49 [gkellogg]
... My position is that the open world assumption, it's clearly multi-valued.
15:12:26 [gkellogg]
... If the meaning is that it can reify multiple triples, then there could be other triples being reified I'm not aware of.
15:12:53 [gkellogg]
... If it's a set of triples, the set cannot be known, because some rdf:reifies statements may exist that I'm not aware of.
15:13:01 [Souri]
q+
15:13:05 [gkellogg]
... A set is open ended (multi-valued).
15:13:17 [gkellogg]
... That makes many-to-many confusing.
15:13:56 [gkellogg]
... As for LPG edges, they don't have a formal definition so you can't talk about denotation.
15:14:28 [gkellogg]
... That was my argument about not having a single predicate for expressing reification, and types could have some advantages.
15:14:44 [gkellogg]
... That is what makes mapping fron RDF to LPG difficult.
15:14:53 [niklasl]
+1 to that
15:14:55 [pchampin]
q?
15:14:58 [gkellogg]
... We should keep rdf:reifies high-level and under-specified.
15:14:59 [pchampin]
ack tl
15:15:06 [gkellogg]
tl: +1 to that.
15:15:32 [gkellogg]
... Does Souri mean forEach semantics for multi-valued?
15:16:08 [gkellogg]
Souri: If you say jon plays sport cricket and footbal, it can be multi-valued.
15:16:42 [gkellogg]
tl: By forEach, I mean if you can use it to say that an annotation applies to each such triple, or the set of those triples.
15:16:46 [pchampin]
q+
15:17:21 [gkellogg]
... You might give a date and want it to apply to each edge individually.
15:17:42 [gkellogg]
... There is a continuum between the two extremes.
15:18:23 [gkellogg]
... In general, I think we can leave it open. If you come from LPG you probably think it's for each edge.
15:18:50 [gkellogg]
... forEach was part of RDF in 1999, but didn't make it into 1.0.
15:19:00 [gkellogg]
... That suggests it's not actually a problem.
15:19:03 [TallTed]
RRSAgent, draft minutes
15:19:04 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
15:19:13 [pchampin]
q?
15:19:20 [pchampin]
ack Souri
15:19:46 [gkellogg]
Souri: We have things that are sets of triples, but not sets of triple terms.
15:20:08 [gkellogg]
... The connection between a reifier connects to individual triple terms, not a set of triple terms.
15:20:22 [TallTed]
s/jon plays sport cricket and footbal/jon playsSport cricket and jon playsSport football/
15:20:27 [gkellogg]
... A set of triples does not really exist.
15:20:52 [gkellogg]
... We could have a set of triple terms sharing a single reifier.
15:22:02 [gkellogg]
... Suppose I say that sports cannot be put in a set, you can't talk about cricket, soccer, etc.
15:22:15 [gkellogg]
... But, in RDF, a set of triples is fundamental, as it defines a graph.
15:22:29 [gkellogg]
... But, triple terms are different than triples.
15:22:57 [gkellogg]
... If it's multi-valued, it cannot connect to a set of triples, which is what would be normal in RDF.
15:23:25 [gkellogg]
... We need to show a need for both views.
15:23:33 [pchampin]
q?
15:23:59 [gkellogg]
tl: The reason triple term is abstract, and occurrences are different topics.
15:24:32 [gkellogg]
Souri: In RDF we don't use a set of URIs. Can we talk about a set of URIs.
15:25:17 [gkellogg]
... We can talk about how to express a Bag, but a Graph is a set of triples. We don't talk about a set of triple terms.
15:25:50 [gkellogg]
tl: We say John has several hobbies and we can talk about the set of those hobbies.
15:26:34 [gkellogg]
pchampin: gkellogg pointed out the Bag collection in RDF 1.0, as those have an open-world assumption.
15:26:40 [AndyS]
q+
15:27:10 [gkellogg]
... The problem is, because of OWA, you can never know it's complete. That's why lists were created, as they're closed.
15:27:34 [gkellogg]
... If a list has been tampered with, you can tell.
15:28:01 [gkellogg]
... Seq was similar, but not closed.
15:28:38 [gkellogg]
... Also, lists have an order; if I had to describe a set, I probably would use a list, but say that order was insignificant.
15:29:05 [pchampin]
:graph :hasTriples (<< s p o >> <<s' p' o' >>).
15:29:20 [Souri]
q+
15:29:27 [pchampin]
:graph :hasTriples (<<( s p o )>> <<(s' p' o' )>>).
15:29:27 [gkellogg]
ack pchampin
15:29:32 [niklasl]
+1 for that example
15:29:42 [pchampin]
ack AndyS
15:30:01 [gkellogg]
AndyS: The other thing about lists is they have to be bnodes to preserve merging.
15:30:11 [pchampin]
ack Souri
15:30:39 [gkellogg]
Souri: Remember we restrict RDF triple terms such that they can only be the object of rdf:reifies.
15:30:41 [AndyS]
Containers have other issues: too many triples - or rather too obviously a triples structure. They are nice(ish) in RDF/XML. Turtle had list syntax from day one.
15:31:15 [gkellogg]
... We would be going against that restriction if we introduce lists.
15:31:48 [pchampin]
q?
15:32:07 [tl]
q+
15:32:12 [gkellogg]
... If you could say rdf:reifies (<<|...|>>, <<|..|>>) we could use this for different modeling purposes.
15:32:24 [gkellogg]
pchampin: Maybe we should use a different predicate.
15:32:48 [pchampin]
ack tl
15:33:15 [gkellogg]
tl: If we have :e1 reifies ..., we could be explicit about what annotations refer to.
15:33:37 [TallTed]
RRSAgent, draft minutes
15:33:38 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html TallTed
15:33:44 [gkellogg]
Souri: Maybe rdf:refiiesSet as a predicate.
15:34:26 [gkellogg]
zakim, end meeting
15:34:26 [Zakim]
As of this point the attendees have been souri, gkellogg, niklasl, TallTed, tl, AndyS, enrico, fsasaki, pfps
15:34:28 [Zakim]
RRSAgent, please draft minutes
15:34:30 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/04/12-rdf-star-minutes.html Zakim
15:34:36 [Zakim]
I am happy to have been of service, gkellogg; please remember to excuse RRSAgent. Goodbye
15:34:36 [Zakim]
Zakim has left #rdf-star
15:34:45 [gkellogg]
rrsagent, bye
15:34:45 [RRSAgent]
I see no action items