00:43:03 RRSAgent has joined #rdf-star 00:43:07 logging to https://www.w3.org/2025/11/11-rdf-star-irc 00:43:08 Zakim has joined #rdf-star 00:48:50 Youngmin has joined #rdf-star 00:49:36 meeting: RDF & SPARQL WG at TPAC 00:50:51 TallTed has changed the topic to: RDF & SPARQL WG -- 2025 TPAC day 1 -- agenda: ( a mystery ) 00:51:10 s/RDF & SPARQL WG at TPAC/RDF & SPARQL WG at TPAC 2025 day 1 00:51:47 present+ 00:51:51 present+ 00:52:04 Enrico has joined #rdf-star 00:52:13 present+ 00:52:34 present+ 00:53:25 present+ 00:54:38 pchampin -- does RDF&SPARQL meeting span midnight? (RRSAgent should be informed.) 00:55:36 I have made the request to generate https://www.w3.org/2025/11/11-rdf-star-minutes.html TallTed 00:55:39 present+ 00:55:44 ora has joined #rdf-star 00:55:46 Ugur has joined #rdf-star 00:55:50 present+ 00:55:58 psowinski has joined #rdf-star 00:55:59 scribe+ 00:56:38 ktk: I suggest we start with a round of introduction, then ora and I will present where the WG is at the moment 00:57:58 Ugur: I work for Depixen (based in London), we want to use RDF in our knowledge graph; new to this WG, trying to figure out how to contribute 00:58:21 csarven: I'm an independant IE, member of the TAG 00:59:14 previous meeting: https://www.w3.org/2025/11/06-rdf-star-minutes.html 00:59:14 next meeting: https://www.w3.org/2025/11/20-rdf-star-minutes.html 00:59:18 ... I'm here to make sure the WG is aware of architectural constraints 00:59:50 piotr: I founded the company Neverblink, we work with streaming RDF, we develop the format JellyRDF 00:59:59 ... also active in the CG for RDF streams processing 01:00:35 Youngmin: I work at KETI. We work in intelligent buildings, we use ontologies to make AI understand buildings. 01:00:43 ... I'm insterested in the status of RDF & SPARQL 01:01:23 Enrico: member of the WG, co-editor of RDF Semantics. 01:01:40 ... Recently more interested in the link between knowledge and data. 01:02:21 Brent Zundel: here on behalf on the AB. I'm here to pick your brain about the W3C process. 01:02:33 pchampin: I'm the W3C staff contact of the WG. 01:02:52 TallTed: I'm with OpenLink, we make Virtuoso. I'm fixing grammar in all your PRs. 01:03:13 ora: I'm the co-chair of the WG, currently working at AWS, member of the Neptune graph DB group. 01:03:20 ... I was a co-editor of the very first RDF spec. 01:03:42 ... Also co-author of the original Semantic Web vision, and contributor to many early SemWeb WGs. 01:04:14 ktk: I'm the other co-chair of the WG, I run Zazuko. 01:04:23 ... Also working with Hanna Bast on Qlever. 01:05:12 topic: message from the Advisory Board 01:05:35 [Brent is presenting the Process improvement task of the AB] 01:05:41 q+ 01:06:34 ack ora 01:08:07 co-chair of WG, not of TAG, correct? 01:10:49 q+ 01:13:12 q+ 01:14:49 ack TallTed 01:17:24 ack pchampin 01:25:04 topic: status of the WG 01:26:07 https://www.lassila.org/publications/2025/lassila-gschwend-kgc2025.pdf 01:26:30 slideset: https://www.lassila.org/publications/2025/lassila-gschwend-kgc2025.pdf 01:27:02 [Slide 1] 01:27:20 ora: ktk and I presented those slides at the Knowledge Graph conference in last may in New York 01:28:03 [Slide 4] 01:28:14 ora: RDF is a widely used knowledge description language 01:28:31 ... half of all the pages in the common crawl dataset contain some embedded RDF in them 01:29:09 [Slide 5 ] 01:29:16 ora: the timeline of RDF is very long 01:29:35 ... in 1997, timbl came into my office, asking what was wrong about the web 01:29:49 ... I answered that I wanted to build agents for the web 01:30:32 ... RDF schema was pretty complete in 1999 but waited until 2004 to become a recommendation 01:31:21 ... the last item in the slide was a bit optimistic... 01:31:57 ... one reason for the delay was that we decided to have all the discussions up-front before going to REC 01:32:11 ... now we are confident that we have considered most of the important questions 01:32:19 [Slide 6] 01:32:32 ora: the motivation was to deal with "statements about statements" 01:32:59 ... from the very beginning, RDF had a reification mechanism 01:34:11 [Slide 7] 01:34:55 ora: different options to talk about a statement: standard reification, or custom "lifting" 01:36:02 ktk: many people working with RDF were quite comfortable with the custom "lifting", so the standard reification was not that used 01:36:15 ... and most people complaining about it were people from other communities (e.g. LPG) 01:36:20 [Slide 8] 01:37:04 [Slide 9] 01:38:13 ora: RDF graphs are mathematical sets, a triple can be only once in a graph 01:38:18 ... changing this would break RDF 1.1 semantics 01:38:51 ... there were discussions about using named graphs, but named graphs have been used for all kinds of purposes ("semantics by convention") 01:39:03 ... we didn't want to hijack named graphs for just once purpose 01:39:40 ... this was a good thing, but also problematic because we need to explain a lot why we did 01:39:47 [Slide 10] 01:40:20 ora: triple-term can be thought of as a representation of a triple as a node 01:40:26 ... they are not unlike literals 01:40:47 ... then we can associate them with an identifier ("reifier") via the new property rdf:reifies 01:40:57 ... we can have any number of reifiers for a given triple 01:41:04 ... which solves the multiple-marriages problem 01:41:19 ... a reifier can also be associated to multiple triple terms 01:41:32 ... this was a very controversial issue in the WG, for various reaons 01:41:51 ... one of them is that they become very similar to named graphs 01:42:06 ... also this structure has no counterpart in LPGs 01:42:15 ... nevertheless, the consensus was to allow this 01:42:27 [Slide 11] 01:43:15 ora: the rdf:dirLangString datatype is for literals with a language tag *and* a base direction 01:43:42 [Slide 12] 01:44:43 pchampin: note that in the meantime, we also covered RDF/XML, which is now also able to express triple-terms 01:44:47 [Slide 13] 01:45:34 ora: reifiers, not triple terms, can be used in the subject position 01:45:58 ... a reason for this constraint on triple term was to avoid people using the triple term when what they actually needed was a reifier 01:46:15 ... also we felt it was easier to add that possibility later on rather than removing it 01:46:21 [Slide 14] 01:46:55 [Slide 15] 01:47:28 [Slide 16] 01:48:37 [Slide 17] 01:50:04 ora: it will be interesting to see what the LPG community will do next 01:50:22 ... they are becoming aware that RDF is a force they need to consider, rather than compete with 01:51:09 ... I will leave ktk answer question 01:51:22 ktk: for those who want to use it, Jena is already implementing it (as an experimental feature) 01:51:27 q+ 01:51:32 q+ 01:51:48 ora: success will be measured by adoption, which needs implementation 01:51:52 ack Enrico 01:52:09 Enrico: it is worthwhile to mention that last week we had another tutorial at ISWC about RDF 1.2 01:52:25 https://www.w3.org/Talks/2025/iswc-tutorial-rdfsparql-12/ 01:52:43 it ran on a full half-day, so it complements that presentation well 01:53:16 Ugur has joined #rdf-star 01:53:36 ora: how was it received? 01:53:48 Enrico: very well, a lot of technical and philosophical questions 01:54:01 ora: we had to take into account 25 years of RDF implementations 01:54:16 q? 01:54:22 ack pchampin 01:54:55 pchampin: another implementation that already implements RDF 1.2 is Oxigraph 01:55:46 ora: one point that I think we need to discuss when RDF 1.2 is how to use these new features in practice 01:55:52 ... we will need dedicated vocabularies 01:56:08 ... I believe that those mechanisms are particularly useful for cross-cutting domains, such as provenance 01:56:13 q? 01:58:09 q+ 01:58:34 pchampin: I would not recommend to use triple-terms for modelling marriages, in fact 01:58:51 ... but it is useful to integrate data that model marriages as nodes and other data that model them as edges 01:59:19 ktk: somebody made a good point last week at ISWC about "unit testing with SPARQL" 01:59:33 ... how easy it is to SPARQL your model is a good quality criterion 01:59:48 Enrico: this touches an important topic that we have not discussed yet 02:00:19 ... there are many different ways the same information can be represented 02:00:39 ... although RDF is too weak to express that two constructs are the same 02:01:11 ... this questions are a huge can of worm, that propably should be tackled with a higher level language 02:01:21 Youngmin has joined #rdf-star 02:01:55 ack csarven 02:02:09 csarven: I'm interested in what RDF / SPARQL 1.2 would bring to implementers 02:02:21 ... now you can use this syntactic sugar to add more information to a triple 02:02:37 ... in the current state, we don't have that view as strongly 02:02:56 ... I'm wondering how people would be relooking at their own datasets 02:03:23 ... did you reflect on this? 02:03:34 ktk: we did, to some extent. 02:04:15 ... We are waiting to see how people explore the new features in ways that may become common design patterns. 02:04:50 ... Also we are RDF geeks who write Turtle by hand, so the syntactic sugar matters to us, but end-users rarely do. This will be hidden to them. 02:04:54 q? 02:05:05 csarven: you have good use-cases, e.g. provenance. 02:05:08 q+ 02:05:18 ... I totally agree that the UI will also make a difference. 02:05:33 ack Enrico 02:05:44 Enrico: we also have to be clear that there are two different classes of use-cases. 02:05:55 ... One is the marriage, which should in fact be done otherwise. 02:06:09 ... The other one is provenance, where the triple-term is actually required. 02:06:53 ktk: thanks, let's break 02:07:04 RRSAgent, make minutes 02:07:05 I have made the request to generate https://www.w3.org/2025/11/11-rdf-star-minutes.html pchampin 02:29:53 Ugur has joined #rdf-star 02:34:13 psowinski has joined #rdf-star 02:38:16 ora: we would be ready 02:40:09 scribe+ 02:40:35 pchampin: I had this topic in my mind for a while. 02:40:48 ... It's about RDF Interoperability note 02:41:00 ... RDF 1.2 has two level of compliance: basic and full 02:41:16 ... basic is everything in RDF 1.2 except triple terms 02:41:28 ... it makes it more complex so that way it can be implemented without. 02:41:46 ... To prevent fragmentation, we want to provide some non-normative guidance 02:42:28 ... about how basic and full could be interoperable. 02:43:18 .. One way is very close to classic RDF reification. 02:43:25 s/../.../ 02:43:49 ... but we use rdf:TripleTerm instead. 02:44:08 ... Like this we could reconstruct the RDF graph and it's entailement preserving. 02:44:33 ... It is a purely syntactic encoding. 02:47:30 ... There are 3 design goals: Information preserving, idempotent, universal 02:47:30 ... For the moment, it is not entierly universal. It will refuse any graph that is hybrid, which means partially encoded and partially not. 02:47:44 ... If you merge them, it cannot be encoded. In retrospect I am not entierly happy with that. 02:48:33 I have made the request to generate https://www.w3.org/2025/11/11-rdf-star-minutes.html TallTed 02:54:48 ... I would like to have the caviat on information preserving instead. 02:54:52 ... If part of the graph is already encoded, the part that is still triple terms would be encoded. 02:54:52 ... It is not information ecoded that way but fully universal. So we would not have to be careful about merging. 02:54:52 ... I don't care if we are not able to re-construct a graph that was partially encoded and partially not. I don't think this is very interesting to reconstruct. 02:54:52 ... But the benefit is that people would not have to be careful about merging, which I think is more useful. 02:54:52 Enrico: I understand it. But my first reaction is I do not like it. 02:54:52 ... we would have to be careful with encoding. Because we don't want to have two blank nodes describing the same triple term. So now I need additionally to minting the blank node to check if the same blank node is not used to describe another triple term. 02:54:52 ... You simply have to redefine the notion of merging. 02:54:52 pchampin: Thanks, I am quite convinced that my proposal is then a bad idea. 02:54:58 ... Good news is I don't have to make changes to the document then. 02:54:58 i/I had this topic/Topic: revising the basic encoding algorithm 03:03:22 RRSAgent has joined #rdf-star 03:04:34 logging to https://www.w3.org/2025/11/11-rdf-star-irc 03:04:34 ... We cannot write it down but semantically it exists. 03:04:34 Enrico: simple example: John loves Marry. There is a denotation of Mary could be the denotation of triple term in itself. 03:05:32 TODO insert missing minutes here 03:05:40 ... in RDF this never was a problem. But the moment we enrich RDF for example with sameAs, we can write a triple term that says "John loves Marry" sameAs Marry 03:06:20 ... Now marry is a proposition. And John loves a proposition. That does not go along with the intended meaning. 03:07:11 ... If we leave the semantics as it is in RDF and RDFS, then we are good. 03:07:33 ... A future OWL might have that problem, they need to be careful. 03:08:30 ... We should say that the definition of Triple Terms need to be well founded. 03:09:12 Enrico: This could be a box in the Semantics document. I'll make a PR 03:09:34 ... Then we finally agreed with Doerthe to close the last PR, we should be ready for CR. 03:10:01 I have made the request to generate https://www.w3.org/2025/11/11-rdf-star-minutes.html TallTed 03:11:06 topic: Status of SPARQL 03:11:36 ktk: we had to wait until things were stabilized in RDF until SPARQL could move forward 03:11:45 ... but now that it's the case, things are moving forward 03:13:06 pchampin: the CWG of RDF Star already prepared a lot of work for SPARQL as well. There are some new functions like is triple term etc. 03:13:17 ... There are also functions related to base directions 03:13:29 ... it's a new kind of literal required for i18n 03:13:52 ... Some things still under discussion is ordering. 03:14:24 ... Then there was a question of weather < or > should be defined on triple terms. Apparently the SPARQL TF is discussing that. 03:14:32 ... But in general the bulk of the work was done in the CWG. 03:15:56 Piotr: At which point should we start implementing RDF 1.2? 03:17:08 pchampin: From our group PoV the RDF specs are now stable. But it is not through yet in the process. 03:18:26 Piotr: Does the WG have a migration path from RDF Star to RDF 1.2 in mind? 03:18:43 q+ 03:19:22 pchampin: The data model has not much changed. The big changes are in the surface syntax. 03:20:03 ... The good news is that if it was valid Turtle Star it's still valid Turtle 1.2. 03:20:56 ack TallTed 03:21:38 TallTed: We can't give you much about how to migration from a random version of RDF Star to RDF 1.2 03:23:33 ktk: if you would export it to Turtle and re-import it, you would be good? 03:24:02 pchampin: If you use the same Turtle file and the same SPARQL query, I would suspect you get the same results. There might be some corner cases. 03:29:22 Kazue has joined #rdf-star 03:29:26 Kazue: We are trying to use SPARQL to search through verifiable credentials. I want to prove that I've graduated at some University. And this University is located in that City. And that city has this popoulation. So that should all be verifiable credentials. 03:29:28 present+ 03:30:13 Kazue: Verifyable statements are statements, that are represented in RDF. And they can be signed by someone, called Issuer. 03:30:48 ... I can say that someone is a graduate of Kobe university. And it is signed by the University. 03:31:30 pchampin: At the moment verifyable credentials are using named graphs, in JSON-LD. 03:32:01 ... Someone at ISWC said we have a problem with it, when we merge it, all the claims get merged to the default graph and the verifications are in the named graphs. 03:33:09 ... How do you cope with this. 03:33:28 Kazue: We are not merging them into one graph, we keep it as a JSON-LD tree. 03:38:00 q+ 03:42:47 s/verifyable/verifiable/ 03:43:27 ack Kazue 03:43:31 https://ssr2022.com/slides/FormalisingLinkedDataBasedVerifiableCredentials.pdf 03:43:51 https://sako-lab.jp/articles/ssr2022_proceedings_dan.pdf 03:46:28 RRSAgent, make minutes 03:46:29 I have made the request to generate https://www.w3.org/2025/11/11-rdf-star-minutes.html pchampin 05:50:11 Zakim has left #rdf-star 06:24:41 TallTed has joined #rdf-star 06:28:36 s/Verifyable/Verifiable/ 06:29:57 s/independant/independent/ 06:29:58 s/insterested/interested/ 06:29:58 s/on behalf on the AB/on behalf of the AB/ 06:29:58 s/Slideset:/Slide set:/ 06:29:58 s/in last may/last May/ 06:30:00 s/semantics by convention/“semantics by convention”/ 06:30:03 s/just once purpose/just one purpose/ 06:30:05 s/reaons/reasons/ 06:30:09 s/entailement/entailment/ 06:30:09 s/entierly/entirely/ 06:30:09 s/caviat/caveat/ 06:30:12 s/ecoded/encoded/ 06:30:14 s/to minting the blank node/to mint the blank node/ 06:30:17 s/Marry/Mary/gi 06:30:19 s/TODO insert missing minutes here// 06:30:22 s/sameAs/sameAs/ 06:30:25 s/weather/whether/ 06:30:27 s/Verifyable/Verifiable/ 06:30:30 s/popoulation/population/ 06:30:32 s/verifyable/verifiable/ 06:30:35 RRSAgent, draft minutes 06:30:36 I have made the request to generate https://www.w3.org/2025/11/11-rdf-star-minutes.html ktk