IRC log of rdfn-meta on 2010-06-27

Timestamps are in UTC.

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rrsagent, set log public
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16:56:33 [ivan]
scibenick: AxelPolleres
16:56:34 [AxelPolleres]
scribe: AxelPolleres
16:57:27 [AxelPolleres]
attendees: MikeDean, ivan, elisa, fabien, thomas, scott, jun, atanas, axelR, AxelPolleres, jie
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16:58:47 [AxelPolleres]
elisa: 2 main topics: 1) named graphs, 2) annotations
16:59:23 [AxelPolleres]
... issues: bnode scope, bnode as graph name, needed vocabulary
17:00:24 [AxelPolleres]
axelR: requirements? named graph as used now, e.g. in Sesame for authentification, can this be solved?
17:00:41 [AxelPolleres]
scott: what do you mean by authentication? signing graphs?
17:00:51 [AxelPolleres]
axelR: sorry, meant authentication
17:01:05 [AxelPolleres]
17:01:27 [AxelPolleres]
mikeDean: also an issue about whether or not more than one NG per doc
17:01:58 [AxelPolleres]
elisa: also, can one graph span multiple docs
17:02:11 [AxelPolleres]
... in earlier discussions we had consensus both is fine/legal
17:03:40 [AxelPolleres]
axel: is syntax N-quads vs TriG style vs. Graphs as literals an issue?
17:03:51 [AxelPolleres]
elisa: that is connected to voabulary
17:04:12 [AxelPolleres]
jun: relation to definitions of named graphs in SPARQL is important
17:04:32 [AxelPolleres]
elisa: let's have one session on named graphs, one session for annotations.
17:04:53 [ivan]
rrsagent, draft minutes
17:04:53 [RRSAgent]
I have made the request to generate ivan
17:05:14 [AxelPolleres]
fabien: n-tuples are one model...
17:07:31 [AxelPolleres]
atanas: datasets for data integration, named graphs
17:07:43 [AxelPolleres]
axel: datesets vs mnamed graphs...
17:07:59 [AxelPolleres]
fabien: what about the default graph/background graph?
17:08:38 [AxelPolleres]
thomas: general solution or specific use case.
17:09:38 [AxelPolleres]
jun: sets of named graphs for any triple are possible in practice...
17:10:06 [AxelPolleres]
ivan: ... and I can query about that whole set, what's the difference between RDF datasets and sets of named graphs?
17:11:12 [AxelPolleres]
axel: are we trying to solve the problem here, or draft a charter?
17:11:21 [AxelPolleres]
fabien: collect/understand problems
17:12:10 [AxelPolleres]
ivan: requirement is max compatibility betwen what we define for NG and how it is defined/used in SPARQL.
17:13:03 [AxelPolleres]
fabien: (SPARQL) Update has an effect on named graphs... if I modify a graph, what does that mean to it's meta-data
17:13:13 [AxelPolleres]
ivan: RDF semantics should be silent about that
17:14:26 [AxelPolleres]
atanas: more important is that Update also need mechanisms to update the meta-data
17:15:14 [AxelPolleres]
ivan: I'd be surprised if a statement on the NG meant that this statement is valid "on all triples in the graph"
17:16:20 [AxelPolleres]
mikeDean: there is a reception that NG is a replacement for reification... your statement implies that it is NOT.
17:17:10 [AxelPolleres]
... for cd:creator etc. NG is a reasonable replacement, not sure for timestamps that apply to triples.
17:18:08 [AxelPolleres]
ivan: then we are back at quads, which can be seen as special syntax for NG
17:19:37 [AxelPolleres]
naso: we want to be able to add metadata to (sets of statements) in a graph.
17:19:45 [AxelPolleres]
17:20:34 [AxelPolleres]
atanas: ist's a matter of adding metadata to subsets/subgraphs
17:22:12 [AxelPolleres]
fabien: from theoretical POV you have a notion of hypergraph that is equivalent to named graph, nested graph etc.
17:22:44 [AxelPolleres]
... one table per named graph could be non-efficient.
17:23:18 [AxelPolleres]
atanas: we need a model that allows to distinguish between the different implementations
17:23:53 [AxelPolleres]
... best model at the moment seems multi-graphs (naso... can you give a reference to multi-graphs)
17:24:17 [AxelPolleres]
thomas: quad plus a fifth element for the triple identifier
17:24:37 [AxelPolleres]
... that's what franz did.
17:25:03 [AxelPolleres]
... for or five is a practical implementation, theoretically 4 is enough.
17:26:00 [FabGandon]
ta one point we need to start collecting use cases, examples and counter-examples
17:26:03 [AxelPolleres]
axel: one layer seems not to be enough to cover all UCs
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17:26:37 [AxelPolleres]
... e.g. if we want to talk about parts of some statemens/individual statements within a graph.
17:27:06 [AxelPolleres]
thomas: syntactically, practically identifying single triples would help a lot.
17:27:33 [AxelPolleres]
scott: we talk about solutions (quads), we should talk about requirements, UCs.
17:27:52 [webr3]
can I ask, is the purpose of a named graph to name (/reference) a distinct set of triples (that never changes)?
17:28:15 [AxelPolleres]
scott: I have another UC, which I didn't present yesterday.
17:28:37 [AxelPolleres]
elisa: we all agree that capturing UCs is essential.
17:29:08 [AxelPolleres]
ivan: we need to know, what is it what the community is using TODAY, what is implemented and how
17:29:50 [AxelPolleres]
... if we find out that e.g. 99% are just quad strores then maye that is an indicator what we should do
17:30:11 [AxelPolleres]
fabien: might not be good for all UCs
17:30:45 [AxelPolleres]
scott: not sure how to handle multiple graph membership could be handled with quads
17:31:11 [AxelPolleres]
fabien: theoretically all can be mapped back to normal graphs, we should just pick one reasonable model on top.
17:31:40 [AxelPolleres]
axelR: we need abstraction on an intuitive way, maybe look at TopicMaps work?
17:32:12 [AxelPolleres]
jie: let's keep in mind semantic consequences on combinations of NGs.
17:33:10 [AxelPolleres]
atanas: currently NGs have not a lot of semantics.
17:33:41 [AxelPolleres]
elisa: let's break, after the break we look at NAso's slides and talk about UCs
17:34:00 [AxelPolleres]
scott: I can present a UC in 3 slides ...
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17:53:41 [FabGandon]
Graph-based Knowledge Representation
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18:06:48 [AxelPolleres]
scibe: jun
18:06:50 [ivan]
scribenick: jun
18:07:44 [jun]
topic: presentation by atanas kiryakov (ontotext) "triplesets: tagging and grouping in RDF datasets"
18:08:33 [jun]
atanas: slide1 ng is an rdf graph with a uri assigned as a named
18:09:00 [jun]
atanas: slide1 sparql spec also has the def of dataset
18:10:05 [jun]
atanas: slide2 in the data integration context, each dataset can be treated as a NG
18:10:45 [jun]
atanas: it's unclear the formal consequences of adding or removing a statement from a NG shoudl be
18:12:30 [jun]
atanas: I am not talking about entailment, even though I used the word consequences
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18:13:58 [jun]
atanas: our solutions to the missing semantics. let a dataset be represented as RDF multi-graphs, a set of quadruples of type <S, P, O, G>
18:18:01 [jun]
atanas: if one statement is in multiple graphs, updating this statement in one graph doesn't mean it will be updated in all other graphs
18:18:22 [jun]
mike: do you implement any relationship between a default graph and a NG?
18:18:41 [jun]
atanas: no, we don't
18:20:17 [jun]
atanas: when you have the spec. of add/remov behavior at both graph and dataset levels, you can do both implementations
18:20:36 [jun]
atanas: management of part of dataset is also needed
18:21:01 [jun]
atanas: e.g. dealing only part of a NG when you try to deal with a sub-dataset
18:22:41 [jun]
atana: the model should allow easy statements with such groups (part of datasets), independent from the NG
18:23:15 [jun]
18:23:54 [jun]
ivan: you are kind of mixing up the abstract data model and the implementations
18:28:04 [jun]
atanas: some statements are true in a specific context, but not in other context. I need metadata about the quads
18:28:31 [jun]
atanas: we have scenarios, we need to group quands, and say things about them. and they are different from grouping triples.
18:30:10 [jun]
atanas: shows the diagram. one triple in multi. NGs. some triples are associated in none triplesets, some are in one tripleset, and some are in multiple triplesets.
18:30:54 [ivan]
Present+ Jeff
18:31:11 [ivan]
Present- Jeff
18:31:16 [ivan]
Present- Jie
18:31:16 [jun]
AxelR: can you create one graph for each triple?
18:31:21 [AxelPolleres]
so.... what if ngs kan not only overlap/nested, but also, don't have to be disjoint... not sure whether I am clear.
18:31:48 [jun]
anatas: that's too fine-grained for our case
18:32:43 [AxelPolleres]
please put the link of the slides on the wikipage.
18:32:58 [jun]
atanas: NG "owns" statements
18:33:40 [jun]
Topic: Elisa's slides about NGs for her ontology modelling
18:34:51 [jun]
ekendall: the odm diagram of NG and graphs
18:34:55 [AxelPolleres]
I firmly believe that we need a simple model.
18:35:15 [jun]
ekendall: a NG has 0..n triples, and a triple belongs to 0..n graphs
18:35:26 [jun]
ekendall: a ng is part of another ng
18:36:00 [jun]
ekendall: a triple in what context belongs to a graph? in uml, you create specialization to state such contextual information
18:36:16 [AxelPolleres]
quads identifying each triple maybe enough even for naso's UC.... why wouldn't they?
18:36:33 [AxelPolleres]
s p o id.
18:36:49 [AxelPolleres]
id :intripleset t1, ... tn.
18:37:02 [AxelPolleres]
id :inNG ng1.
18:37:03 [jun]
ivan: i can have a NG having one triple. for me a quad is just a name for another atomic singleton NG
18:37:06 [AxelPolleres]
that's it
18:37:42 [jun]
mike: sparql doesn't the notion of subgraphs
18:38:05 [jun]
ivan: I just want to query one graph, I don't care anything else
18:38:17 [AxelPolleres]
something like g1 rdfs:GraphIncludes g2 might be a useful extension of RDFS semantics.
18:38:37 [jun]
18:39:09 [jun]
ivan: for me, the abstract view presented by elisa wors
18:39:45 [mscottm]
mike: but in some cases, we must query a million singleton named graphs
18:39:55 [jun]
AxelR: who creates a statement and when is different from who has the authority to access the statement
18:40:36 [mscottm]
scott: that points to the notion of making statements about quads in some types of implementations, i.e. one case is actually quintuples
18:41:18 [mscottm]
..quintuples is where we are trying to manage metadata about named graphs such as many singleton named graphs
18:41:50 [jun]
tomlurge: we need syntax sugar to ease the implementation issue
18:42:49 [AxelPolleres]
quads and named graphs are entirely interchangeable for most UCs.
18:42:59 [jun]
elisa's slides is at p45 of
18:46:00 [jun]
FabGandon: we need to align the different notions of NGs.
18:48:03 [jun]
ivan: it scares me to see the notion that we would need quadruples on top of rdf triples
18:49:29 [jun]
mike: should NG be really a sub-class of RDF graph?
18:49:43 [jun]
elisa: I might need to go back and revisit it after the discussions on this context
18:49:59 [jun]
mike: it would also make sense to align the concept from sparql spec.
18:50:18 [jun]
ivan: subclass in the UML sense. Just to the precise!!
18:51:12 [jun]
elisa: we just took the NG paper and modelled in UML. that's all we did.
18:52:02 [jun]
AxelR: we need to keep the model intuitive, otherwise it won't be useful
18:52:38 [jun]
ivan: what we do with singletons; the semantics of the quads; or whether we stay with "set" kind of semantics
18:53:48 [jun]
ivan: we need to have all the discussions and identified issues well recorded on the wiki
18:53:50 [AxelPolleres]
Axel's charter wishlist: 1) standardise SPARQL datasets plus a notion of graph inclusion and semantics for it, 2) extendto RDFS
18:54:04 [jun]
ivan: there seems to be different interpretations about Jeremy's paper
18:54:35 [jun]
AxelPolleres: what the graph notion means semantically? in terms of RDF/RDFS semantics? and the relationship with the sparql
18:55:13 [jun]
ivan: we should get the documentation on the wiki done fore lunch and discuss annotations after lunch
18:55:28 [AxelPolleres]
3) upwards compatibility with non-named graphs.
18:55:35 [jun]
FabGandon: at one moment, we need to specifiy what we need to the "Syntax" group
18:55:59 [AxelPolleres]
in the sense that a non-named graph is a dataset only consisting of a default graph?
18:56:22 [AxelPolleres]
definition of dataset merge as a generalisation of graph merge?
18:56:48 [AxelPolleres]
note that this latter would include talking about bnode scope in named graphs, likely...
18:57:11 [AxelPolleres]
(if wanted, I can put that on the wiki)
18:57:11 [jun]
Topic: atanas shows his use cases about tripleset
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19:01:17 [AxelPolleres]
4) upwards compatibility with SPARQL datasets
19:01:20 [jun]
atanas: each singleton triple belongs to a graph, and we have metadata for each of this singleton graph
19:01:58 [jun]
FabGandon: I see named graphs in the right example expressed in triplesets too
19:02:35 [jun]
atanas: we want to be able to express in the example much prettier if using NGs
19:03:38 [jun]
mike: it might also help to show the use of reification in your example too
19:04:12 [jun]
FabGandon: we also should try to express in N3
19:05:03 [jun]
Topic: Use case by Scott
19:05:47 [jun]
scott: w3c hcls have a KB years ago, as a kb warehouse
19:06:50 [jun]
scott: we have multiple sparql endpoints. at each sparql, we have a bunch of named graphs
19:07:18 [jun]
scott: we would like to know what NGs behind each endpoint and what are there
19:07:40 [mscottm]
19:09:11 [jun]
scott: who created the rdf, which version of database, etc
19:09:12 [mscottm]
19:09:24 [mscottm]
19:09:50 [jun]
scott: I don't where I go and look for such information when going to a sparql endpoint
19:11:25 [AxelPolleres]
Good additional issue: How do named graphs semantics relate to FYN?
19:11:26 [jun]
FabGandon: you have follow-your-nose, take a uri of a NG, you get the property of that graph. is this what you want?
19:12:21 [jun]
scott: how to create query federation by following the NGs. FYN could be a good way to go if it works
19:13:01 [jun]
ivan: I don't see how your requirement is directly related to quads
19:13:36 [jun]
ivan: it's requirement to sparql 1.1., to provide descriptions to named graphs
19:14:36 [AxelPolleres]
scott, please check
19:14:40 [jun]
ivan: you should take a look at the sparql service description document
19:15:34 [jun]
FabGandon: we should collect all the different names related to Named Graphs
19:15:54 [jun]
ivan: does sparql use NG?
19:16:10 [AxelPolleres]
fabien: nested graphs, named graphs, dataset.
19:16:16 [jun]
ivan: does sparql use the term named graphs?
19:16:31 [AxelPolleres]
19:19:14 [jun]
topic: editing the wiki to track identified issues
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19:28:02 [AxelPolleres]
19:28:05 [AxelPolleres]
19:28:14 [AxelPolleres]
I put my wishlist on the wiki page
19:33:10 [FabGandon]
we need to indentify all the notions that are used here and compare them, a number of disagreement are on the terms more than the definitions: named graphs, typed graphs, typed nested graphs, typed nested named graphs, quadruples, triple sets, n-tuple, included graphs, etc.
19:35:50 [AxelPolleres]
19:40:21 [ivan]
rrsagent, draft minutes
19:40:21 [RRSAgent]
I have made the request to generate ivan
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rrsagent, make records public
20:48:59 [mdean]
scribenick: mdean
20:51:08 [mdean]
back from lunch
20:51:19 [mdean]
review updates to
20:52:03 [mdean]
Axel's wishlist
20:52:45 [timbl]
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20:52:56 [timbl]
RRSAgent, pointer?
20:52:56 [RRSAgent]
20:53:40 [mdean]
Naso: efficient addition/removal of statements in datasets?
20:53:49 [mdean]
... hypergraph or multi-graph
20:54:46 [tomlurge]
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20:56:03 [mdean]
moving on to annotations
20:56:29 [dwood]
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20:56:42 [jun]
scribenick: mdean
20:56:42 [mdean]
Axel: specific annotation domains and their semantics
20:57:53 [timbl]
Darn, missed named graphs.
20:58:23 [mdean]
... perhaps should be handled in other group
20:59:15 [AxelPolleres] gives a summary of issues we discussed so far... now discussiong whether concrete annotations are in scope or noe
20:59:28 [mdean]
Fabien: practical/scope reasons not to work on specific vocabularies
20:59:33 [timbl]
I wish people would not confuse graphs and documents. graphs can be named indirectly though documents' URIs, just as strings can and xml infosets can, but the URI does not identify the graph in the sense of the I in URI.
21:00:00 [mdean]
... lots of good progress in vocamps
21:00:25 [AxelPolleres]
@Anchakor, the idea here was to define some mechanism that allows to define an inclusion relationship between them, e.g. rdf:subGraphOf
21:01:07 [mdean]
Jun: foundation for providing annotations should be in RDF Core
21:01:50 [AxelPolleres]
+1 to that point of Jun
21:01:54 [mdean]
Fabien: named graphs important for annotations
21:02:04 [AxelPolleres]
(foundations should be layed)
21:02:09 [timbl]
AxelPolares, log:includes seems to match that need
21:02:53 [mdean]
Jun: may require additional features depending upon how named graphs are implemented
21:03:09 [mdean]
DavidWood: also impacts bnodes, etc.
21:03:35 [AxelPolleres]
timbl, fair enough, except that we might want - in a rubber-stamped standard - give that a URI in the rfd: ns?
21:03:58 [timbl]
21:04:09 [AxelPolleres]
we're on the same page...
21:04:13 [timbl]
(If we need names graphs, how did we ever get by without named Strings, and Named Integers)?
21:04:45 [mdean]
Jun: need to agree on meanings of annotations
21:04:58 [mdean]
dwood: good to include metadata about graph in the graph itself
21:05:14 [mdean]
... helps, and commonly done now
21:06:18 [timbl]
Well, commonly done now is metadata about a document in the document like: <> a IRCLog.
21:06:22 [AxelPolleres]
(timbl, this is about making graphs/triples derefernceable, resources are dereferenceable already ... except if you'r talking about the literals-as-subject-issue, for which I'd refer rather to the syntax or semantics breakout groups)
21:06:53 [mdean]
dwood: naming graphs in documents vs databases - people now ready to move on
21:06:57 [AxelPolleres]
I should have said "referable" rather than "dereferenceable", probably, didn't mean to imply HTTP
21:07:09 [timbl]
No, I'm not talking about literals-as--subject, I assume that will be fixed.
21:07:39 [mdean]
Elisa: best practices or something more than that
21:08:05 [mdean]
Ivan: WG needs to specify named graphs - not sure about annotations (probably no)
21:08:20 [AxelPolleres]
don't understand what "how did we ever get by without named Strings, and Named Integers" means then
21:08:34 [timbl]
Strings and Integers are unnamed.
21:08:38 [timbl]
That works fine.
21:08:42 [timbl]
So are graphs in N3.
21:08:56 [mdean]
Ivan: already have more on list than envisaged - keep WG quick and small
21:08:57 [timbl]
You can name things around them using relastions like log:semantics
21:09:10 [timbl]
But you don't actually name the graph or the string or the literal.
21:09:17 [mdean]
... should be handled somewhere (else) by community
21:10:00 [dwood]
Tim, do you have concerns that literals-as-subjects could result in many RDF graphs without any URIs in subjects or objects? That is a usage scenario that has been discussed around here.
21:10:04 [FabGandon]
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21:10:04 [mdean]
Scott: include examples of use in documents
21:10:59 [mdean]
Axel: SPARQL WG time-allowed features
21:11:01 [timbl]
I am worried that the beauty of N3 which can solve so many problems is going to be messed up by a great asymmetry in a new language with named graphs.
21:11:13 [mdean]
Ivan: messy
21:11:36 [mdean]
... necessary for SPARQL 1.1, given no workshop like this one
21:11:46 [timbl]
dwood, I am not at all concerned about graohs not having URIs in theory any more than I a numbers not having URIs.
21:11:49 [mdean]
... re-chartered 3 times for IPR reasons
21:13:11 [timbl]
I don't know why it is so difficult to explain the need for graphs to be literals in the language just like strings. The problem is it is too onbvious to me.
21:13:20 [mdean]
Sandro: charter leaves some room for WG to prioritize
21:13:41 [mdean]
Elisa: requirement from provenance WG
21:13:49 [timbl]
Yes, Anachor, you can use sameAs I think to name any literal, graph or not.
21:13:59 [mdean]
Ivan: separate path for provenance
21:14:12 [timbl]
21:14:15 [FabGandon]
Feedback, proposal, opinions, references gathered about named/nested/annotated graphs in the W3C Workshop on RDF next steps:
21:14:40 [mdean]
Ivan: WG has to specify what named graphs are - syntax, semantics, etc.
21:14:52 [AxelPolleres]
timbl, graphs as literals is one way to tackle this issue, named graphs is another... no?
21:14:58 [Anchakor]
timbl: great, if owl:sameAs was merged in rdf namespace it would wash away a lot of pain... and I agree with similarity of graphs and literals
21:15:07 [mdean]
Jun: use case gathering process for named graphs?
21:15:12 [mdean]
Ivan: probably
21:15:29 [AxelPolleres]
my personal idea would be that all that can be done if we make RDF datasets as used in SPARQL a first-class citizen of RDF.
21:15:34 [timbl]
AxelPolares, no, it is not an equally good method.
21:15:49 [mdean]
... UC can be formal document or more implicit - to be decided by WG
21:15:57 [timbl]
If you have graph literal syou can do anything, including any form of named graohs.
21:15:57 [mdean]
... RDFa didn't have a separate UC document
21:16:24 [timbl]
If you have named graohs then you cannot have graoph literals and you can't just write a little N3 rule without sma nems.
21:16:25 [mdean]
Elisa: use cases for provenance should be considered for named graphs
21:16:35 [mdean]
... add e.g. provenance, annotations, etc.
21:16:59 [timbl]
(BTW my login is not accepted for editing the wiki )
21:17:25 [mdean]
Elisa is actively editing the charter
21:17:36 [AxelPolleres]
sure, and vice versa, "named graphs that aren't named" can simply be represented by bnodes ... that's just a dual solution in my opinion, isn't it?
21:17:56 [timbl]
anchakor, in N3, owl:sameAs is just "=" so the namespace is not seen.
21:18:28 [AxelPolleres]
one could provide syntactic sugar looking similar to N3 graph literals for that case in a Turtle/N-triples/N3 syntax standardisation, no?
21:18:30 [mdean]
Elisa: leave in document for now
21:18:52 [mdean]
... any proposals?
21:18:53 [timbl]
AxelPolleres, write { ?x a Man } => { ?x a Human}. in named graphs, then.
21:19:01 [mdean]
... TBD based on named graphs
21:20:07 [AxelPolleres]
timbl, RDF rules a la N3 rules is not in scope of an RDF WG, IMO, but a matter of defining a RIF dialect with an N3 surface syntax, rather.
21:22:25 [timbl]
AxelPolleres, write { foo.html licence l:lgpl } chron:before "2007-06-7Z". in named graphs, then.
21:22:42 [timbl]
That is a provenance use case I assume
21:22:46 [mdean]
Elisa: want to be able to reason over annotations
21:22:55 [mdean]
Axel: provide examples
21:23:48 [AxelPolleres]
RDF Dataset: { foo.html licence l:lgpl }_:c . _:c chron:before "2007-06-7Z".
21:24:22 [AxelPolleres]
this dataset consists of one named graph and the default graph contains the annotation for that graph... makes sense?
21:25:06 [timbl]
Well yes, but it is messy.
21:25:17 [mdean]
Axel: should provide extensibility mechanism for annotations
21:25:29 [FabGandon]
messy ?
21:26:10 [AxelPolleres]
Axel: We should provide an extensibility mechanism for annotations, exemplify it, in terms of how annotations can be given a semantics.
21:26:20 [timbl]
wel, having to intrducce the bnode _:c i smessy.
21:27:09 [FabGandon]
it is likely that we will discourage bnodes for graph names
21:27:17 [timbl]
re RDF Dataset: { foo.html licence l:lgpl }_:c . _:c chron:before "2007-06-7Z". --- does the default dataset contain the triple { foo.html licence l:lgpl } ?
21:27:39 [FabGandon]
to me yes
21:27:54 [mdean]
Ivan: other 2 groups are finished - not sure about semantics
21:28:00 [timbl]
In other works, will a simple SPARQL query for that trip return it?
21:28:01 [FabGandon]
and I would say it also contains the triple _:c chron:before "2007-06-7Z"
21:28:03 [AxelPolleres]
timbl, same as for lists ... :s :p (1 2 3)
21:28:22 [timbl]
If so, we have a problem, in that it isn't true, as it was only true before 2007.
21:29:20 [mdean]
Sandro: avoid using term Named Graph - N3 has graph literals
21:30:02 [timbl]
21:30:43 [mdean]
Elisa: suggest RDF Graph Identification
21:31:09 [FabGandon]
I agree : lets talk about "rdf graph indentification"
21:31:42 [timbl]
Do you want just to name it or to express its contents?
21:31:46 [AxelPolleres]
I am fine with that, I just think we shouldn't preclude naming
21:31:57 [timbl]
For a literal, it sidentity is only its contents.
21:32:11 [timbl]
The identity of "chat" the string is just its contants.
21:32:34 [timbl]
You can't have two strings "chat" and "chat" and maintain they are different.
21:33:34 [timbl]
If you give graphs names, will you be able to have identical graphs which are though not equal because they don't have the same name? Ugh... remember you will have to do logic wit these things.
21:33:42 [Anchakor]
what about graphs composed by applying a function on some other graphs? (ex: a graph representing an union of 2 different graphs)
21:33:53 [timbl]
You will nee to make things depend on subgraohs.
21:34:06 [FabGandon]
my opinion: we need (1) a mechanism to identify a graph (2) a mechanism to say a triple is included in one or several identified graphs.
21:34:10 [AxelPolleres]
timbl, we have a generic proposal for giving semantics to annotations (such as time in your example), cf. ... that should work independent of the syntactic representation, be it graph literals or named graphs.
21:34:11 [timbl]
You will need to derive a graph from a string by parsing it.
21:34:29 [Naso]
21:34:56 [jun]
+1 to fabien
21:35:04 [AxelPolleres]
What's wrong with subgraphs? if we give a semantics to log:includes/rdf:subgraphOf?
21:35:50 [AxelPolleres]
Fabien, and log:includes/rdf:subgraphOf allows exactly that, or no?
21:36:04 [mdean]
all groups have finished
21:36:11 [Naso]
Alex, see the final slide in the slides - you have the example why doing the same with sub-graphs is a bit cumberstone
21:36:33 [Naso]
I meant Axel, sorry
21:36:48 [Anchakor]
I wish this vocabulary was more propagated:
21:36:59 [FabGandon]
if graphs are triple sets, and graph inclusion is set inclusion I think we can have a simple and clear graph inclusion mechanism
21:37:03 [timbl]
AxelP, You didn't include N3 as alternatives in your slidest even though we have been doing just what you are talking about for amost 10 years with it?
21:37:17 [AxelPolleres]
naso, not if we provide syntactic sugar a la N3 for it
21:37:30 [AxelPolleres]
... as discussed with timbl further up in IRC
21:37:34 [FabGandon]
but then again the question here is not to solve these questions but to decide on their inclusion in the charter
21:37:56 [FabGandon]
my opinion is yes let's have this question of inclusion in the charter
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21:41:14 [timbl]
:axel f:knows :ivanherman true ‘‘in’’ ?
21:42:02 [AxelPolleres]
timbl, true, that is an ommission in the syntactic representation part, but those slides were not meant to propose syntax, just to raise the issue that we need to fix/agree on a syntax, and - equally important - to discuss a generic semantics framework for annotations.
21:42:13 [timbl]
We would say <> log:semantics [ log:includes {axel f:knows :ivanherman }] without inventing any more sugar
21:42:19 [timbl]
and then reason over that
21:42:56 [AxelPolleres]
... as mentioned above, I think that the N3 way of writing it fits with a named graph/quad way of writing it.
21:44:38 [timbl]
In fact I think when you combine the annotations with the data in the graphs in your logic you will need the same generality as cwm has to write rules about what is inside a graph.
21:45:43 [timbl]
Like { ?doc author Axel. ?doc says { ?axel knows ?y }} => { Axel knows ?y }.
21:45:51 [AxelPolleres]
the syntax I have in the slides, e.g. " :axel f:knows ivanherman {}" was meant as an abstract notation for an annotation, and there are several alternatives to write it.
21:45:57 [timbl]
Anyway, late here, gtg
21:46:55 [AxelPolleres]
thanks for the discussion, appreciated, timbl, anyways, I still think that the rules part of N3 is not a core RDF working groups concern.
21:47:06 [mdean]
back to #rdfn
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21:47:26 [AxelPolleres]
rrsagent, make minutes public
21:47:26 [RRSAgent]
I'm logging. I don't understand 'make minutes public', AxelPolleres. Try /msg RRSAgent help
21:47:42 [AxelPolleres]
rrsagent, make records public
21:47:54 [AxelPolleres]
rrsagent, draft minutes
21:47:54 [RRSAgent]
I have made the request to generate AxelPolleres
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