IRC log of rdf-star on 2024-05-16

Timestamps are in UTC.

15:55:51 [RRSAgent]
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logging to https://www.w3.org/2024/05/16-rdf-star-irc
15:55:55 [Zakim]
RRSAgent, make logs Public
15:55:56 [Zakim]
please title this meeting ("meeting: ..."), pchampin
15:56:02 [pchampin]
meeting: RDF-star Working Group focused meeting
15:56:48 [pchampin]
agenda: https://www.w3.org/events/meetings/0a6aa6e3-635c-42c2-baba-938c76b6ef01/20240516T120000/#agenda
15:56:48 [agendabot]
clear agenda
15:56:48 [agendabot]
agenda+ Feedback KG Conference
15:56:48 [agendabot]
agenda+ Discuss Profiles -> 1 https://github.com/w3c/rdf-star-wg/wiki/RDF-star-profile-%22transparent%22 -> 2 https://github.com/w3c/rdf-star-wg/wiki/RDF-star-profile-%22functional-opaque%22 and possibly Singleton Properties -> 3 https://www.w3.org/2024/05/02-rdf-star-minutes.html#t08
15:57:18 [pchampin]
pchampin has changed the topic to: RDF-start WG Focused Meeting - 2024-05-16 -- https://www.w3.org/events/meetings/0a6aa6e3-635c-42c2-baba-938c76b6ef01/20240516T120000/
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15:58:37 [enrico]
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15:59:52 [pchampin]
scribe+
15:59:58 [gkellogg]
present+
16:00:01 [pchampin]
present+
16:00:02 [ora]
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16:00:04 [thomas]
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16:00:14 [ktk]
p+
16:00:25 [pfps]
present+
16:00:27 [thomas]
present+
16:00:30 [gtw]
present+
16:00:41 [niklasl]
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16:00:43 [ora]
present+
16:00:49 [ora]
chair: ora
16:01:10 [eBremer]
present+
16:01:11 [gkellogg]
rrsagent, generate minutes
16:01:13 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/05/16-rdf-star-minutes.html gkellogg
16:01:20 [AZ]
present+
16:01:24 [olaf]
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16:01:26 [niklasl]
present+
16:01:54 [TallTed]
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16:02:18 [AndyS]
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16:02:27 [AndyS]
present+
16:02:57 [pchampin]
topic: report of the Knowledge Graph Conference
16:02:57 [ktk]
Zakim, open item 1
16:02:57 [Zakim]
agendum 1 -- Feedback KG Conference -- taken up [from agendabot]
16:03:12 [pchampin]
ora: the KGC keeps improving.
16:03:21 [pchampin]
... There was a panel on graph standards.
16:03:43 [pchampin]
... I gave a short overview of what's going on in our WG. There seemed to be a lot of interest in that.
16:03:49 [olaf]
present+
16:04:02 [pchampin]
... There was also a lot of interest in RDF-LDP alignment.
16:04:13 [gtw]
s/LDP/LPG/
16:04:17 [pchampin]
... People expressed interest in reasoning for LPG, shapes for LPG.
16:04:39 [pchampin]
... Another topic was the use of LLMs wth KGs.
16:04:53 [pchampin]
... Souri, you were here as well. Anything to add?
16:05:04 [Dominik_T]
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16:05:11 [Dominik_T]
present+
16:05:12 [TallTed]
present+
16:05:14 [TallTed]
Zakim, who's here?
16:05:14 [Zakim]
Present: ktk, eBremer, rubensworks, fsasaki, tl, ora, niklasl, AndyS, TallTed, pfps, olaf, gtw, doerthe, Souri, Dominik_T, AZ, enrico, thomas, gkellogg, pchampin
16:05:16 [TallTed]
RRSAgent, draft minutes
16:05:17 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/05/16-rdf-star-minutes.html TallTed
16:05:23 [Zakim]
On IRC I see Dominik_T, AndyS, TallTed, olaf, niklasl, pfps, thomas, ora, enrico, gkellogg, eBremer, RRSAgent, AZ, rhiaro, Tpt, ktk, driib5, gb, Zakim, pchampin, csarven, gtw,
16:05:23 [Zakim]
... agendabot
16:05:33 [pchampin]
Souri: Alister mentioned the simplicity of the LGP model (e.g. property values limited to scalars).
16:05:50 [gtw]
s/LGP/LPG/
16:05:56 [TallTed]
s/p+//
16:06:08 [pchampin]
... It is important that we provide a way to align RDF with LPGs. People who don't need it don't have to use it.
16:06:44 [pchampin]
ora: we are definitely not working in a vacuum. People are observing and following.
16:07:06 [TallTed]
previous meeting: https://www.w3.org/2024/05/03-rdf-star-minutes.html
16:07:08 [TallTed]
next meeting: https://www.w3.org/2024/05/17-rdf-star-minutes.html
16:07:09 [pchampin]
... Now the GQL is out -- provided you pay a few 100$ for access.
16:07:32 [pchampin]
Zakim, open next agendum
16:07:32 [Zakim]
I see a speaker queue remaining and respectfully decline to close this agendum, pchampin
16:07:32 [enrico]
present+
16:07:39 [pchampin]
q?
16:07:41 [enrico]
q+
16:08:34 [pchampin]
ack Souri
16:08:42 [Souri]
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16:08:42 [pchampin]
ack doe
16:08:45 [pchampin]
ack enrico
16:08:47 [Souri]
present+
16:08:48 [pchampin]
Zakim, open next agendum
16:08:48 [Zakim]
agendum 2 -- Discuss Profiles -> 1 https://github.com/w3c/rdf-star-wg/wiki/RDF-star-profile-%22transparent%22 -> 2
16:08:50 [Zakim]
... https://github.com/w3c/rdf-star-wg/wiki/RDF-star-profile-%22functional-opaque%22 and possibly Singleton Properties -> 3 https://www.w3.org/2024/05/02-rdf-star-minutes.html#t08
16:08:50 [Zakim]
... -- taken up [from agendabot]
16:08:56 [doerthe]
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16:08:59 [gtw]
q+
16:09:02 [doerthe]
present+
16:09:12 [pchampin]
enrico: to summarize the state of the "profile" business
16:09:21 [pchampin]
... we have two profiles with largely overlaping syntax.
16:09:32 [pchampin]
... implementers can decide to implement one, or the other, or both.
16:09:47 [enrico]
https://github.com/w3c/rdf-star-wg/wiki/RDF%E2%80%90star-examples-of-profiles
16:10:04 [Souri]
q+
16:10:11 [pchampin]
... we need to decide if "both" is possible, and if so to decide on a syntactic marker to distinguish which is intended.
16:10:20 [pchampin]
... Niklas wrote a number of examples. (link above)
16:10:23 [ora]
ack gtw
16:10:46 [pfps]
q+
16:11:05 [enrico]
q+
16:11:11 [pchampin]
gtw: my understanding of the two profiles was in the use of different predicates.
16:11:16 [niklasl]
(Enrico wrote the examples, I mostly reformatted.)
16:11:44 [pchampin]
... My concern is that the syntactic sugar is defined in a way that favors one of the profiles.
16:12:12 [pchampin]
... But looking at Enrico's examples, I am not sure. Both of them seem to use the same syntax.
16:12:40 [pchampin]
enrico: the opaque triple terms have a quote around, but that's just a proposal. A nice one, in my opinion.
16:12:45 [niklasl]
Another form thrown around uses <' s p o '> instead of <<'s p o'>>
16:12:55 [TallTed]
RRSAgent, draft minutes
16:12:56 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/05/16-rdf-star-minutes.html TallTed
16:13:02 [pchampin]
... it would be fine as it does not conflict with the IRI syntax.
16:13:38 [pchampin]
... I'm not too concerned about syntax.
16:13:45 [AndyS]
q?
16:14:00 [pchampin]
... We are not concerned about the predicate, but about the ability to distinguish the opaque profile from the transparent profile.
16:14:21 [pchampin]
gtw: do you see this as a possibility that implementors implement both?
16:14:44 [pchampin]
enrico: I have no crystal ball, but I expect everyone would implement both. I don't see a reason to implement only one.
16:15:00 [ora]
q+
16:15:03 [ora]
ack Souri
16:15:09 [pchampin]
gtw: it sounds like it would be possible to implement both; two predicates seems an important aspect of this design.
16:16:03 [pchampin]
Souri: rdf:refies could be used in triple terms, like :a rdf:reifies << :b rdf::reifies << :c :d :e >> >> .
16:16:34 [pchampin]
... Is there any demand for being able to do that? My sense is that it would be very low.
16:16:55 [pchampin]
... If that is to be included in the standard, I would prefer it to be a SHOULD than a MUST.
16:17:13 [pchampin]
... Implementations would like to not support it for performance.
16:17:31 [ora]
ack pfps
16:17:32 [pchampin]
enrico: the current abstract syntax forbids it. We can change that, but I don't think it would make much sense.
16:17:45 [pchampin]
pfps: a couple of points should be made.
16:18:08 [pchampin]
... 1. People talk of these as profiles, but they are different from OWL profiles (different proposals, vs. parts of a bigger language).
16:18:18 [niklasl]
One example would be for reifying a data event where something other was reified.
16:18:37 [pchampin]
... 2. Transparent and opaque don't matter much with rdf:reifies. It tends to make transparent things behave much like opaque things.
16:18:41 [pchampin]
ora: can you elaborate?
16:18:59 [pchampin]
pfps: with a reifier, you don't get the kind of inferences you would get with a regular triple.
16:19:35 [pchampin]
... With transparency, if two triples have the same denotation, you can mix and match their components.
16:19:47 [pchampin]
... But this does not apply to reifiers.
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16:20:07 [ora]
ack enrico
16:20:12 [ora]
ack ora
16:20:17 [pchampin]
enrico: that's fine. Different reifiers of the same triple can denote different things (a triple, an event).
16:20:19 [doerthe]
q+
16:20:21 [eBremer]
present+
16:20:38 [pchampin]
ora: a question, just to clarify:
16:21:03 [pchampin]
... in enrico's definition, a tuple with rdf:reifies in the predicate position is not defined as a triple, right?
16:21:08 [pchampin]
enrico: yes
16:21:27 [pchampin]
ora: in a SPARQL query, are those tuples invisible to SPARQL triple patterns?
16:22:06 [pchampin]
enrico: you can consider that we have two kinds of triples: legacy-triples, and reifies-triples. But they are all triples.
16:22:20 [pchampin]
... But all should be visible to SPARQL.
16:23:09 [pchampin]
ora: I started wondering whether the association between the reifier and the triple term is really part of the graph, or if this is merely part of our book-keeping.
16:23:37 [pchampin]
q+
16:23:39 [thomas]
q+
16:24:02 [ora]
ack doerthe
16:24:21 [pchampin]
enrico: if we want to exclude reifies-triples, then they are more like "declarations", but there were arguments against separating declarations from statements.
16:25:05 [pchampin]
doerthe: we got here (transparent / opaque profile) because we wanted to avoid having a reifier reifying multiple triples.
16:25:32 [pchampin]
... ora, as you were concerned about this, would the opaque profile address your profile?
16:25:47 [enrico]
q+
16:25:50 [pchampin]
ora: I do believe it helps us.
16:26:19 [niklasl]
My impression has been that the transparency version does not work with LPGs due to it's many-to-many nature; but that the distinct opaque version makes it clearer "a priori" which graphs are "LPG-compliant"?
16:26:39 [pchampin]
... I'm extremely happy that the WG has indulged us in this regard.
16:26:56 [pchampin]
... I understand both sides of the argument. The way I look at it there are multiple dimensions to it.
16:27:06 [ora]
ack pchampin
16:28:17 [Souri]
q+
16:28:27 [ora]
ack Souri
16:28:30 [pchampin]
pchampin: what are we trying to achieve by preventing reifies-triples from being triple terms?
16:28:53 [pchampin]
... Granted this is a corner case, but I would prefer a more regular model.
16:29:29 [pchampin]
Souri: yes, for completeness, we may want to allow it, but in practice people would not need that.
16:29:50 [pchampin]
... From an implementation point of view, I would make it more difficult for us to support that.
16:30:05 [gtw]
+1 on this being an issue for efficient implementation
16:30:20 [pchampin]
... I'm not saying it should not be part of the standard, but if it is, the standard should allow vendors like us to not implement it.
16:30:37 [pchampin]
q+
16:30:37 [AndyS]
q+
16:30:44 [ora]
ack thomas
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16:30:54 [pchampin]
ora: I can't even think of a use-case for those.
16:30:58 [fsasaki]
regrets+
16:31:16 [gtw]
obvious use case would be data provenance: "when did Ora insert this rdf:reifies triple?"
16:31:21 [ora]
ack enrico
16:31:25 [pchampin]
thomas: why not get rid of the abstract triple term as well, and define 4 elements in a triple (s p o id)?
16:32:06 [pchampin]
enrico: you still need to define the relation between the triple term and the id.
16:32:16 [Souri]
q+
16:32:28 [pchampin]
thomas: then we need two kinds of quads. So what?
16:33:02 [pchampin]
enrico: I read a lot of LinkedIn posts on this topic. You can see two camps: those who want transparent, and those who want opaque.
16:33:05 [pchampin]
... So we need both.
16:34:00 [ora]
ack pchampin
16:34:37 [pchampin]
... I wanted to give an example of how we can encode LPG in RDF, making them richer.
16:35:10 [pchampin]
s/an example/examples/
16:35:46 [niklasl]
Very much a corner case, but e.g.: <record/version-2> rdf:reifies <<( <publication> rdf:reifies <<( <book> :publisher <org> )>> )>> . # in version 1 the <publication> "reifier" just reified another triple (the publishedAt date).
16:35:59 [ora]
ack AndyS
16:36:01 [enrico]
q+
16:36:32 [pchampin]
pchampin: I don't have a use case for reifying reifies-triples, but I am concerned that ensuring this restriction will be a hassle
16:37:11 [pchampin]
... You would need to check every triple before turning it into a triple-term.
16:37:24 [pchampin]
AndyS: To add to that: this would happen quickly with SPARQL CONSTRUCT.
16:37:50 [pchampin]
... With variable you need to check it at runtime. It would create runtime errors, which would create usability problems.
16:37:51 [pchampin]
q+
16:38:10 [enrico]
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16:38:15 [enrico]
present+
16:38:39 [pchampin]
ora: is this an argument for letting all flowers bloom, or for turning them into declarations?
16:38:49 [pchampin]
AndyS: I don't know how it would look as a declaration.
16:38:52 [ora]
ack Souri
16:39:25 [pchampin]
Souri: reacting to what Thomas said about having 4 terms.
16:39:31 [AndyS]
Also - rdf:refies in property paths
16:40:29 [ora]
ack enrico
16:40:31 [pchampin]
... I'm ok with having rdf:reifies. But if we wanted 4 components, there would be a way to distinguish opaque vs. transparent.
16:40:44 [pchampin]
... But I'm not pushing for the 4-components solutions.
16:41:21 [pchampin]
enrico: if we used declarations instead of reifies-triples, we would be unable to query this.
16:41:32 [pchampin]
... That's why at this point I don't think we should go for declarations.
16:43:01 [pchampin]
... I suspect the regularity would not create too much implementation problems, but that's not my field.
16:43:09 [ora]
ack pchampin
16:43:11 [niklasl]
(this would be named triples)
16:44:17 [enrico]
:-)
16:44:46 [pchampin]
pchampin: to AndyS' point about irregularity: we already have that with literals as subject with SPARQL CONSTRUCT
16:45:07 [pchampin]
... we are ignoring it. Could we do the same with rdf:reifies in triple terms?
16:45:12 [Souri]
q+
16:45:19 [ora]
ack Souri
16:45:24 [pchampin]
... (playing the devil's advocate, I prefer regularity :->)
16:45:28 [pchampin]
AndyS: this would be more confusing
16:45:58 [pchampin]
Souri: and a SPARQL CONSTRUCT could end up putting triple-terms in the subject position
16:46:06 [pchampin]
AndyS: yes, or bnodes in predicate position
16:47:05 [niklasl]
q+
16:47:37 [pchampin]
Souri: to pchampin's point, we could handle rdf:reifies in triple terms like we are currently treating those other irregularities
16:47:37 [ora]
ack niklasl
16:47:54 [pchampin]
niklasl: question about the LPG case and transparency.
16:48:16 [enrico]
q+
16:48:21 [pchampin]
... If you migrate an LPG to RDF, you will and up with a lot of opaque stuff that you might not want to be opaque.
16:48:36 [ora]
ack enrico
16:49:12 [pchampin]
... It seems to me that the opaque profile came from the need to restrict the cardinality of rdf:reifies, not from a wish from LPG people to have only opaque.
16:49:33 [ora]
q+
16:49:40 [pchampin]
enrico: cf. pchampin's counter-example with symmetric properties and transparent triple-terms.
16:50:05 [pchampin]
... We need opaque for a one-to-one correspondance.
16:50:35 [pchampin]
q+
16:50:39 [ora]
ack ora
16:50:47 [pchampin]
... If we want to talk about what these things mean (which LPGs don't do at all), you expand with transparent triple-terms.
16:50:56 [niklasl]
q+
16:51:12 [pchampin]
ora: that's a good point. In many ways, LPG people (if there is such a group) don't understand when we talk about semantics.
16:51:24 [pchampin]
... For them the semantics is only in their head.
16:52:45 [pchampin]
enrico: there is a Property Graph Schema Language WG
16:53:01 [pchampin]
... apparently, they consider that once a PG has a schema, they can reason with it.
16:53:18 [pchampin]
ora: this is a new thing for their group.
16:53:26 [ora]
ack pchampin
16:55:26 [pchampin]
... The have use-cases for validating PGs, which is a valid.
16:55:44 [ora]
ack niklasl
16:55:53 [pchampin]
pchampin: my belief is that a one-size-fit-all tansformation will never be entirely satisfying.
16:56:13 [pchampin]
... more accurate transformation will require a kind of "context", similiar to JSON-LD.
16:56:22 [thomas]
q+
16:56:51 [pchampin]
niklasl: we seem to represent the lack of known semantics with opaque triples.
16:57:08 [pchampin]
...any syntax suffers from this lack, unless they are designed as concrete syntaxes for RDF.
16:57:54 [pchampin]
... If you have to edit your data once you realize you needed RDF, to change triple-terms from opaque to transparent, that might be an issue.
16:57:58 [thomas]
q-
16:58:47 [pchampin]
ora: we are over-time, sorry thomas, we could not talk about singleton properties
16:58:54 [pchampin]
... thanks everyone, good conversation. See you next week.
16:59:08 [pchampin]
enrico: there will be a Semantics TF meeting tomorrow.
16:59:18 [pchampin]
RRSAgent, make minutes
16:59:20 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/05/16-rdf-star-minutes.html pchampin
16:59:52 [pchampin]
s/topic: report of the Knowledge Graph Conference/
16:59:55 [pchampin]
RRSAgent, make minutes
16:59:56 [RRSAgent]
I have made the request to generate https://www.w3.org/2024/05/16-rdf-star-minutes.html pchampin
17:03:23 [pchampin]
RRSAgent, bye
17:03:23 [RRSAgent]
I see no action items