RDF Core Working Group IRC logs for 2001-08-02

These are the logs from the RDF Core Working Group IRC chat.

Thanks to Dave Beckett for the logger software that produced them.

You are here: Logs Home / 2001-08-02

[00:00:26] dajobe
phayes: publishing a doc that erfers to anon _:bob and really want to do that
[00:00:40] dajobe
... if I can't mean the same thing by the same name, that name is no use of all
[00:00:52] dajobe
danc: nature is that there is no name in rdf/xml and can't refer to it
[00:01:03] dajobe
phayes: then I shouldn't generate _:bob
[00:01:22] dajobe
danc: yes, but this is ntriples and _:bob can't be seen outside
[00:01:41] dajobe
fmanola: then this can't come up?
[00:01:56] dajobe
phayes: are you allowed to use _:bob
[00:02:04] dajobe
danc: no, you use "something"
[00:02:14] dajobe
phayes: then I cannot refer it to you directly
[00:02:23] dajobe
danc: yes, you have to use other mechanism
[00:02:50] dajobe
jang: there are transient docs on the web and fetch them, _:bob etc. are transient identifers you want them to behave lie that
* danbri scribes
[00:04:03] danbri
frank: it is one thing to talk about two '_bobs'... It is a very different use case if I, perusing doc1 and getting a genid _bob, returns to source and say "hey, you know that thing you called _bob"...
[00:04:16] danbri
pat: thats the case i had in mind
[00:04:35] danbri
sergey: suggestion... Don't use N3 please. We've barely a grip on RDF/XML.
[00:05:00] danbri
dan: we didn't see these disagreements until we had ntriple to make situation explicit
[00:05:43] danbri
emiller: <shows example with /2001/08/01-ex1 and -ex2.> (@todo: link to doc from em)
[00:05:50] danbri
[00:06:03] danbri
jan: theres a mechanism question w.r.t. what pat's sayinh
[00:06:19] danbri
"we have _bob from 2 docs... we want to go back and say more stuff about 'it'"
[00:06:40] danbri
"you can use identifying properties about it
* danbri disagrees (quietly)
[00:07:20] danbri
graham: the reason i showed example in ntriples was cos we've decided to use this to describe what parsers do
[00:07:36] danbri
"the unfortunate part of the example was my writing _bob instead of _243234234234324
[00:07:45] danbri
"parser needs to write some kind of labelling for the ntriple for.
[00:08:00] danbri
"now if two docs happen to parse to same ntriple form, incl. genids...
[00:08:19] danbri
"are we going to make parsers responsible for making globally unique genids
[00:08:32] danbri
"or do we couch this in terms of ids relative to a document
[00:09:38] danbri
frank: a query rather than an assertion: "let's pop the stack... seems we've gone in a fairly complicated manner discussing a number of relevant topics. But we started out here with some pretty straightforward questions, ie. firstly whether we want generated identifiers, then whether we want to distinguish them from URIs (either semantically or syntactically)
[00:09:57] danbri
"i don't know that we've done much to answer those questions, or to answer their converse: if we don't like something is the result any better?
[00:10:15] danbri
"if we don't like generated identifiers, we have things that aren't identified, what do we do
[00:10:24] danbri
brian: we've decided that
[00:10:37] danbri
dan: we didn't decide they were URI
[00:10:52] danbri
brian: i thought we had made progress
[00:11:12] danbri
..."that we agreed we can distinguish these things 'in the model'
[00:11:30] danbri
frank: did we decide that they had the characteristics of URIs
[00:11:37] danbri
pat: decisions was...
[00:11:54] danbri
"we agreed there wouldbe a way of distinguishing the 'distinguished nodes' from 'undistinguished ones'
[00:12:00] danbri
dan: i didn't agree to new syntax for this
[00:12:05] danbri
pat: some way...
[00:12:09] danbri
brian: to tell them apart
[00:12:16] danbri
pat: ...syntactically...
[00:12:30] danbri
emiller: we have 3 interpretations on the overhead
[00:13:10] danbri
dan: make the first one a non-URI,
[00:13:26] danbri
emiller: some way of uniquely identifying it, that is or isn't or looks like a uri
[00:13:45] danbri
dan: the wg has ruled out the 3rd situation
[00:13:56] danbri
..."i heard that you could tell the difference in the output
[00:14:15] danbri
"since seeing http://blah in output couldn've been there in the input
[00:14:40] danbri
pat: what's wrong with saying because it contains 'genid' in it
[00:14:44] danbri
dan: not without talking to god
[00:15:03] danbri
..."not in our charter"
[00:15:42] danbri
emiller: (to pat) a lot of us are coming to this from a web architecture p.o.v....
[00:15:50] danbri
brian: dave has the words from previous decision
[00:16:16] danbri
frank: there's a reverse side of it... When you generated this thing that's clearly distinguishable from a URI... Is it therefore _not_ a URI?
[00:16:34] danbri
..."what are its characteristics?
[00:16:38] dajobe
question was: http://ilrt.org/discovery/chatlogs/rdfcore/2001-08-01.html#T22-57-09
[00:16:39] danbri
frank: yes, acc to the URI spec
[00:16:48] danbri
dave reads from logs:
[00:18:02] danbri
emiller: some people are thinking they can peek inside syntactic substructure of uris
[00:18:38] dajobe
answer was: http://ilrt.org/discovery/chatlogs/rdfcore/2001-08-01.html#T23-18-30
[00:19:33] danbri
dan: the words he wrote rule out interpretation 3
[00:19:40] danbri
(someone pls post the 3rd example)
[00:20:32] danbri
pat: similar to one saying, i'll write an axiom in logic with a relation name called 'Not'
[00:20:50] danbri
dan: the text he read says we can tell these apart
* danbri now agrees
[00:21:17] danbri
dan: this info is not enough to tell us
[00:21:28] danbri
pat: why can't we say what the rules of the language are?
[00:21:55] danbri
dan: nowhere in rdf 1.0 does it say we can't have http://purl.org/var/.... is not allowed...
[00:22:03] danbri
"now into the opacity argument for not inspecting URI substrings
[00:22:15] danbri
graham: URIs are not our language (ie. IETF spec)
[00:22:17] danbri
[00:22:18] danbri
[00:22:19] danbri
[00:33:31] danbri
dan: some issues are kinda arbitrary, we owe to world to flip coins
[00:33:42] danbri
...i feel this is a non-arbitrary decisions, needs doing properly
[00:34:05] danbri
(discussion of Vegemite-based incentives)
[00:34:13] danbri
dan: i'm happy to defer to another issue
[00:34:23] danbri
emiller: i'd like to end with something we can accomplish
[00:34:32] danbri
...do you think we can do that in 30 mins
[00:34:48] danbri
pat: i voted no and caused a bunch of trouble
[00:35:13] danbri
..."i'd be happy to change and say yes, so long as we ack that we need to introduce notion of scoping, and be crystal clear
[00:35:32] danbri
"it'd be a mistkae to say they have an existential interpretation and have vagueness about their scope
[00:35:48] danbri
sergey: i want to support your (dan's) suggestion by proposing another use case
[00:36:05] danbri
emiller: pat, dan, sergey agreeing...??!
[00:36:23] danbri
sergey: "the case i'm suggesting... trying to factor out all the different concepts we have in our mind...
[00:36:45] danbri
"if we have something we think are anonymous nodes in the document... is there a way to point to this thing in another document?
[00:37:08] danbri
dan: my answer is 'no'
[00:37:25] danbri
sergey: there's this axiom of the web, that rdf allows folk to say anything about it
[00:37:48] danbri
graham: it doesn't, you can talk about the same entity
[00:38:09] danbri
jan: you _can_ providing you're talkikng about a sub-document... ie. make an instantiation of the document... you know what the anonymous resource is...
[00:38:32] danbri
..."database analogy: run a query on a db, you can tell its identity in the database. but i can't publish the private id as a uri
[00:39:04] danbri
pat: a realisation... i think jos said all along... "you can publish a document... if someone can
[00:39:28] danbri
pat: if the original document _is_ enough to pick it out, (jos: by value) then yes you _can_ describe it further
[00:39:48] danbri
brian: my worry, we spent a whole bunch of time on anon nodes... we set out questions...
[00:40:12] danbri
"once a node gets into the model, can i tell it apart, we had that questoin... I want to make sure. Can we confirm we said "yes!"
[00:40:30] danbri
danc: we've only answered it if we rule out 3rd interpretation (@todo: url overhead)
[00:40:57] danbri
brian: <rdf:Description><foo:bar>foobar</foo:bar></rdf:Description> ...->... _ <foo.bar> "foobar"
[00:41:32] danbri
questoin: what goes here< after the '_'
[00:41:32] danbri
dan: ??? (missed)
[00:41:32] danbri
pat: nobody reading any document generated from the xml would ever be able to get hold of the id
[00:41:45] danbri
pat: of course in ntriples it looks public
[00:42:03] danbri
pat: but if in the egs we use 'http:' it sure looks public
[00:42:11] danbri
brian: notion of public doesn't feel quite precise enough
[00:42:20] danbri
..."same question as sergeys 3rd...
[00:42:40] danbri
brian: there are 3 things that could go in here...
[00:42:49] danbri
"___ <foo.bar> "foobar"
[00:43:07] danbri
brian: dan is asking that we don't allow URIs here
[00:43:31] danbri
strawpolll: can it be a uri
[00:43:33] danbri
most folk: no
[00:43:36] danbri
pat: don't care
[00:43:44] danbri
mike: i'd like it to be a uri and parse substructure
[00:43:56] danbri
sergey: we can have a special namespace
[00:45:13] danbri
danbri: dan persuade me. folk might write bad RDF/XML that used our magic namespace for genids. therefore we can't gurnatee the distinction
[00:45:15] dajobe
danc also said - no, you can't lok inside URI
* danbri nods
[00:45:25] dajobe
miked then said - want to parse fragment ids
[00:45:34] danbri
brian: so it can't be a uri
[00:45:39] danbri
Capturing this:
[00:45:49] danbri
we agree it can't be a URI.
[00:46:12] danbri
frank: generated identifiers have a distinguished representation from URIs
[00:46:46] danbri
mike: i'd like to see us say 'we reserve any fragments beginning with an underscore
[00:46:59] danbri
...that way you might know eg what doc it came from
[00:47:02] danbri
...in rdf:ID
[00:47:14] danbri
dan: then you lose expressive power; you lose ability to say 'there exists'
[00:47:24] danbri
marK: maybe you want several types of genids
[00:47:31] danbri
pat: please please don't use a variable as a name
[00:47:52] danbri
jan: this ... doesn't really work. you go to a source, get a doc back; you do again, you get it back. these things are transient in the web.
[00:48:08] danbri
mike: there's nothing to keep the parser from providing an id
[00:48:13] danbri
dan: i suggest thats a bug
[00:48:46] danbri
brian: as i udnerstand the issue with the rdf:ID="_id43454" solution... if i read it in twice, i'm going to geneate the same URI
[00:48:53] danbri
mike: if you use same tool
[00:49:16] danbri
brian:...but you have no way to know that that's about theS same rsource
[00:49:27] danbri
...you're parser is asserting identity when has no right to do so
[00:49:41] danbri
mike: [...] can use daml:equiv...
* danbri (didn't capture that)
[00:50:02] danbri
pat: that was what bothered me about _bob
[00:50:07] danbri
...someone else might use it
[00:50:18] danbri
mike: i'd want them to use full URI for doc
[00:50:20] danbri
martin: yes
[00:50:40] danbri
dan: i use '_bob' here, i can't use that _thing_ in any other formula
[00:51:00] danbri
pat: if you were to write that in rdf/xml you'd not see '_bob'
[00:51:14] danbri
dan: in ntriples: an implicit backwards E in front of _:
[00:51:35] danbri
martin: these bobs can't be matched across documents
* DanC_ wonders when the meeting is scheduled to adjourn
[00:52:02] danbri
emiller: i'm a little confused about this convesation...
[00:52:45] DanC_
on opacity, is Mike Dean or PatH here on IRC? the opacity axiom is documented, in draft form, at http://www.w3.org/DesignIssues/Axioms.html#opaque
[00:53:00] danbri
..."we've had compelling test cases / experiences in last few years. W.r.t. serey's point. While we say anyone can say anything about anything, here perhaps we can't. Possible, quite probably, that some things may not have names. Those things without may be difficult to further describe
[00:53:23] danbri
"given our current focus, rdfcore, if you give something an ID, you have good chance of merging data...
[00:53:44] danbri
"for those things that don't... not our business to standardise stuff best done in privacy of own computer
[00:54:00] danbri
em: we might eg like sha1 digests, but not our business to specify
[00:54:21] danbri
pat: that's not the issue. Not about knowing 'the' name, but a name.
[00:54:40] danbri
pat: is the act of giving something a name that big a burden that we can't ask them to do it
[00:54:46] danbri
dan: rdf 1.0 did not make that burden
[00:54:58] danbri
"question is, how do we interpret the doc in our 1.0 syntax
[00:55:11] danbri
pat: rdf m+s text is utterly unclear about notion of anon nodes/resources
[00:55:29] danbri
dan: but we DID tell people to write rdf/xml in this form
[00:56:09] danbri
emiller: the 1st intepretation is what we meant first time round; "i feel terrible for setting community back 4 years, not beating the s**t out of editors/WG 1st time round, but that's the situation
[00:56:15] danbri
ora: it's not all your fault!
[00:56:29] danbri
emiller: so, clean up our mess. That's where we're at...
[00:56:34] danbri
dan: problem is that the implementors have done 2nd/3rd thing
[00:56:44] danbri
frank: can someone clarify diff between 1st and 2nd?
* danbri requests emiller's doc for the records. URL please!
[00:57:38] danbri
frank: "if point is to interpret the 1st one as an existential qunatifier... what's the difference between my wanting to refer to that something, that ?x, versus referring to some arbitrary named genid. I think there's a difference.
* barstow is enjoying this discussion and would love to see it continue but I'm wondering if we have to stop at the top of the hour because the published schedule said the meeting would end at 6:00pm ...
[00:58:00] danbri
dan: pat made this crystal clear. In assertional case same entailment; in query case, nontrivially different
[00:58:09] danbri
dan: we can't go into queries
[00:58:11] danbri
frank: yes...
[00:58:21] danbri
[00:58:48] danbri
pat: (attemptign to sum up)
[00:59:07] danbri
"suppose we have existntials, not generated names, there's no real difference logically. what's thefunctional difference?
[00:59:34] danbri
"you lose a little functionality. if there's a handle provided for every existential. if there's no handle, you lose a little functionality.
[00:59:49] danbri
dan: if we want a handle, make it a uri
[00:59:53] danbri
pat: yes, you could take that line
[01:00:30] danbri
[01:00:32] danbri
[01:00:48] danbri
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[01:00:57] danbri
emiller: i feel progress from last few years...
[01:01:03] danbri
pat: issues are becoming clearer...
[01:01:07] danbri
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* jhendler lurking (Invite as member of W3-SW-CG)
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* DanC_ wonders if the WG came to any conclusion on anon-resource etc.
[14:58:04] AaronSw
Doesn't seem like it from the logs...
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[16:12:35] barstow
Ora: Pat and I have been thinking and we agree
[16:12:40] barstow
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[16:12:59] scribe
... we are concenred about the identity of anon nodes
[16:13:10] scribe
... we do know the identity of the annonnodes
[16:13:24] scribe
... the distictness is reserved.
[16:13:40] scribe
Node -a-> 1
[16:13:46] scribe
Node -b->2
[16:14:18] scribe
[16:14:37] scribe
In the serialization syntax, we give no names to these nodes
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[16:15:50] scribe
Pat: the realization that I have, if I do the MT as attached to the graph, then issues like scope of exist quant go away becauset there are no scopes in the graph
[16:16:48] scribe
... ... In N-Trpiles, annonNodes have ttheir own syntax. The annonNode is unique.
[16:17:52] scribe
ACTION: Pat - I'll re-word the MT wrt my new insight.
[16:18:37] scribe
Pat: wrt entailment, if two nodes have same URI, they can be merged; if they do not, they must not be merged.
[16:18:47] jhendler
(err, I mean what school do you attend)
[16:19:19] scribe
Pat: there is no way in [core] RDF to do the graph merging that Eric showed yesterday.
[16:19:37] scribe
EricM: you are correct, it can be done with additional rules - is not part of core RDF
[16:20:20] scribe
Pat: this resolves wether things are public or private [Brian's issue]
[16:20:35] scribe
Pat: this resolves DanC's issue with existen quantifier
[16:20:56] scribe
Pat: the annonNodes do have ID but this has nothing to do with the graph
[16:22:24] scribe
Frank: if you think of the model as being the graph, the nodes in the ggraph have identify; if I merge the graph, the nodes still have identity; the annonNodes just don't have URI.
[16:23:21] scribe
Frank: wrt serialization syntax, what characteristics do the annonNodes have?
[16:24:46] scribe
Pat: with N-Triples, annonNode are identified by their unique syntax
[16:25:25] scribe
Frank: if you try to merge multiple N-Triple docs, the app must keep info about where the triples came from
[16:25:57] scribe
Steve: N-Trples therefore is not a good syntax
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[16:28:00] scribe
Graham: 2 vars are distinct if they have diff tags or if they appear in diff n-triples expressions
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[16:28:43] scribe
... when combining 2 ntriple expressions, all of the tag nodes are assigned arbitrary tags such that distinct nodes always have disnt tags in the resulting expression
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[16:28:57] scribe
mike: I'm worried about exposing internal names
* GK-f2f I think words to cover this are in: http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001Jul/0397.html
[16:29:41] scribe
Pa: must differentiate naming the node and giving a name to the thing the node denotes
[16:29:51] scribe
[16:30:04] scribe
Ora: this is NO change to the M&S spec!
[16:30:11] scribe
Pat: I agree!
[16:30:52] scribe
Mike: in the case where internal names need to be exposed, you will loose the fact that it was anon?
[16:30:55] scribe
Pat: yes.
[16:31:33] scribe
Eric: what does this say about the issue - are these thing distinguishable?
[16:31:54] scribe
Pat: Yes.
[16:32:34] scribe
DaveB: I don't understand the need to add scoping N-Triples.
[16:32:46] scribe
Pat: if you merge on the graphs, there is no problem.
[16:32:56] scribe
DaveB: you merge graphs, not N-Triples.
[16:33:51] scribe
... [not n-triples docs]
[16:34:04] scribe
Jan: we've said scope of N-Triples is the N-Triples doc.
* GK-f2f so I have a program that reads two different N-triples documents, and spits out N-triples thayt bresult from merging their graphs -- I'd describe that as merging the N-triples documents
[16:34:22] scribe
Steve: I think we still have to deal with the scoping issue.
[16:34:36] scribe
... Ntriples are forcing us to do that.
[16:35:13] scribe
Arno: we ran into this issue at Adobe.
[16:35:43] scribe
... We have diff docs and compound docs. We solved it by
[16:36:07] scribe
... first thinking not about annonNodes but implicitly named [have a name, wwee dont know what it is]
[16:36:25] scribe
... We have a mechanism to refer to them.
[16:36:54] scribe
... What we've said is consistent with our design.
[16:37:11] scribe
Graham: Ntriples is a syntax.
[16:37:59] scribe
Brian: I think we have some agreement but need to test if we are talking about the same thing.
* GK-f2f and a "document" is a character string that matches poroductiions from the "distinguished symbol" of the N-truiples grammar ... i.e. a "sentence" of the Np-triples syntax.
[16:38:36] scribe
... I think Ora and Pat said:
[16:38:48] scribe
... the fundamental model is the GRAPH MODEL!
[16:39:06] scribe
... Ntriples is a syntax for a graph [a serialization foor a graph]
[16:39:30] scribe
... We can have more than one graph.
[16:39:35] scribe
Pat: yes!
[16:40:27] scribe
Brian: when I merge ntriples, the semantics is that I'm merging the graphs.
[16:41:28] scribe
... If we have the two graphs, we can't just concatentate the corresponding n-triples; must first change some names
[16:41:58] scribe
Brian: does the MT theory, Pat?
[16:42:21] scribe
Pat: yes, the MT must be based on the graph, not on N-Triples.
[16:42:40] scribe
... won't need the set of triples in a document.
[16:43:09] scribe
Brian: we have an RDF serialization
[16:43:17] scribe
... we will also have a grammar
[16:43:43] scribe
... we will define semantics by defining a mapping from serialization to n-triples
[16:43:58] scribe
... from n-triples, we have a MT
[16:44:15] scribe
... Why do we have to change that?
[16:45:03] scribe
Pat: the arrow from ntriples to MT must now go through the graph
[16:45:09] scribe
... the graph has a MT
[16:45:25] scribe
... the advant: separates some issues
[16:46:01] scribe
Graham: will we have a MT based on the graph [not the ntriples]
[16:46:52] scribe
Ron: want the graph in the middle; put MT in an arc; put n-triples as an arc, put RDF/XML as a arc
[16:47:32] scribe
Ron: if we split an ntriples doc, how to put it back together?
[16:47:57] scribe
Pat: we can break up graphs.
[16:48:28] scribe
... In the graph, nodes are nodes.
[16:50:14] scribe
Ron: use case is controlled vocabularies
[16:50:33] scribe
... a node may have lots of info
[16:50:41] scribe
... may only want to send some of the info
[16:50:52] scribe
... can send the identity of the node
[16:51:39] scribe
jan: if you need to talk about it, give it a URI!
[16:54:07] scribe
Sergey: I'm not convinced we're all talking about the same thing.
[16:55:37] scribe
... want to explore using annonNodes as existential quantifiers, etc.
[16:56:06] scribe
... By looking at these other approaches, we could get more.
[16:57:23] scribe
danbri: I would like to hear Sergey's view.
[16:57:50] scribe
... I would be willing to give up some RDFS time.
* AaronSw thinks you're going around in circles
[16:59:00] scribe
---- Sergey -----
[16:59:46] scribe
[Sergey projects a document that contains his model.]
[17:00:02] scribe
ACTION: Sergey - send this document to the WG mail list
[17:00:27] scribe
Annon nodes as existential variables
[17:00:46] scribe
URI constants: c = {c1,...,cN,...}
[17:00:53] scribe
{ exists, & }
[17:01:04] scribe
Variables: {x1,...,xN,...}
[17:01:26] scribe
graph/document = formula without free variab les (most general consensus?)
[17:01:51] scribe
Applications exchange documents in intermediate format (BLOB), but get formulae (graphs) in the end
[17:02:28] scribe
d1 = t(c1, c2, ce)
[17:02:28] scribe
d2 = exists x1 t(c1, c2, x1)
[17:02:35] scribe
d3 = exists x1 [ t(c1, c2, x1) & t(x1, c3, c4) ]
[17:02:43] scribe
[17:02:55] scribe
Let -> be entailment
[17:03:09] scribe
d1 = d2 <=> d1 -> d2 and d1 -> d1
[17:04:21] scribe
ad 0): t(c1, c2, c3) -> exists x1 t(c1, c2, x1) [Inference that DanC want]
[17:04:36] scribe
ad 1): d1 = exists x1 t(c1, c2, x1)
[17:04:54] scribe
d2 = exists x2 t(c1, c2, x2)
[17:05:21] scribe
d1 -> d2 and d2 -> d1 => d1 = d1 (fine)
[17:06:03] scribe
ad 2): d1 = exists x [ t(c1, c2, x) & t(x, c3, c4)]
[17:06:16] scribe
How split?
[17:06:43] scribe
[ed note: ... d1=>d1=d2 above]
[17:07:02] scribe
d1' : exists x1 t(c1, c2, x1)
[17:07:26] scribe
d1'' : exists x2 t(x2, c3, c4)
[17:08:03] scribe
Merge: d1''' = exists x1 t(c1, c2, x1) & exists x2 t(x2, c3, c4)
[17:08:34] scribe
d1 -> d1''', but d1''' -/-> d1 => d1 != d1'''
[17:08:58] scribe
irrerversibel change when docs are split and merged (bad?)
[17:09:21] scribe
ad 3: impossible to refer to anon. node in another document withing the model
[17:09:40] scribe
d1 = exists x1 t(c1, c2, x1)
[17:09:59] scribe
d2 = exists x2 t(c1, c2, x2)
[17:10:15] scribe
no way to ask: is x1 in d1 same as x2 in d2?
[17:10:28] scribe
Anonymous nodes as local constants:
[17:10:41] scribe
(Implementaiton perspective)
[17:10:57] scribe
URI constants: C = {c1,...,cn,...}
[17:11:57] scribe
Local constatns: PRG1 = {l1_1,...l1_N,lll}, PRG2 = {l2_1,...,l2_N,...}
[17:12:11] scribe
Rule: prg1 cannot see constants in document
[17:12:41] scribe
ad 0): t(c1,c2,c3) -/->, <-/- t(c1,c2,l1) [fine]
[17:13:08] scribe
ad 1): d1 = t(c1, c2, l1_1), second parse d2 = t(c1,c2,l1_2)
[17:13:18] scribe
d1 != d2 [bad?]
[17:14:13] scribe
[17:14:35] scribe
[ed. note: I give up - assume Sergey will post this his file to the list ...]
[17:16:06] scribe
[17:16:17] scribe
[17:17:38] scribe
o A does not caont URI (disjoing) If A and C overlap, we cannot distinguish anon. nodes from the others. But: since the same procedure for assigingin constants from A, this is irrelevant. A can be viewed as subset of C that is extremely unlikely to be used
[17:18:25] scribe
o Application that neeed not communicate may not local IDs. If communicate using syntax that contains "holes", fine. No global autogeneration algorithm required.
[17:19:01] scribe
o If no standard assignment algorithm is required, ad 1) is still violated (parsing twice)
[17:20:46] scribe
[17:21:13] scribe
Sergey: there can be a formal mechanism to help base arguments about anon. nodes.
[17:21:41] scribe
... point 2: there are multiple options for implementing anon. nodes [they all have advantages and disadvantages]
[17:22:45] scribe
... want to ground the decisoion. This also helps define the application semantics.
[17:22:55] scribe
Jan: this is very useful. However, your existance proof is false.
[17:23:28] scribe
... You have no way of knowing where things come from.
[17:23:56] scribe
... The algorithm doesn't reflect that a URI may return the same thing through time.
[17:25:14] scribe
Pat: the question is what is the semantics. Is is temporary [the doc]?
[17:25:26] scribe
... M&S is talking about graphs.
[17:27:09] scribe
Sergey: I think explicit genids would be useful.
[17:27:34] jhendler
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[17:28:03] scribe
Brian: if you parse the same doc, should an anon description have the same identity?
[17:30:25] scribe
Ron: if everyone generates the same identifier for an anon node, it could be useful but it also could be dangerous.
[17:30:37] scribe
... That's the choice: useful vs dangerous.
[17:30:54] scribe
danbri: it is very dangerous.
[17:31:22] scribe
Brian: can you do more things this way?
[17:32:07] scribe
Ron: you can do more things because then you can hang additional stuff off of it.
[17:32:19] scribe
Jan: there are better ways to do this.
[17:32:39] scribe
Frank: what exactly is the question?
[17:33:27] scribe
Brian: do you need everyone to use the same algorithm?
[17:33:49] scribe
Ron: if folks agree on an algorithm, you can do additional stuff.
[17:35:49] scribe
Pat: I don't think these examples are helpful. They introduces more confustion. It doesn't talk about the graph.
[17:36:21] scribe
... We don't need to introduce the variables.
[17:37:32] scribe
Eric: we need to put a stake in the ground and move on. We need to focus on the graph to agree on stuff.
[17:38:38] scribe
Pat: I'll update the MT based on the graph within a week.
[17:58:11] scribe
======== Break Over =========
[18:00:20] GK-f2f
RDF Syntax -- Dave Beckett Leads
[18:01:51] GK-f2f
[18:02:57] GK-f2f
slide 2
[18:03:18] GK-f2f
slide 3
[18:03:24] GK-f2f
[18:03:27] GK-f2f
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[18:03:31] jang
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[18:04:34] jang
(talks about benefits of ntrlpes as simple serialisation)
[18:04:41] jang
slide 4
[18:04:50] DanCon
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[18:05:21] jang
dave'd been looking at reexpressing the grammer in terms of the infoset, rather than '<' etc
[18:05:39] jang
grammar looks simpler, smaller
[18:06:23] jang
we o xml syntax -> ntriples -> graph -> MT
[18:06:27] jang
[18:06:39] jang
points at:
[18:06:57] jang
[18:07:16] jang
dave points out, as an example, the 6.3 entry in the table
[18:07:40] jang
dve's had to invent a syntax for expressing XML infoset
[18:07:57] jang
slide 5
[18:08:31] jang
change to slide: <=> "the graph" in each case
[18:08:50] jang
dave mentions other formal proposals for syntax notations
[18:08:55] jang
slide 6
[18:09:09] jang
answer to "is ntriples sufficient?" DB: yes
[18:09:15] jang
(db = dave beckeytt)
[18:09:36] jang
still open on question 2: what formalisms should be used to express grammar
[18:09:45] jang
=> slide 8
[18:09:47] jang
and done
[18:10:01] jang
wy is BNF so bad?
[18:10:27] jang
we can use BNF, but sould be expressed in terms of infoset, not <, & etc
[18:11:04] jang
PH: ntriples syntax may bem misleading
[18:11:14] jang
URIRef and anonnode should be changed
[18:11:19] jang
DB: I've already changed that
[18:11:52] jang
[18:11:57] jang
there are two questions
[18:12:05] jang
1. how we repsent the grammar formally and precisely
[18:12:12] GK-f2f
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[18:12:17] jang
2. how do we define the transform from rdf/xml into core representation
[18:12:27] jang
(and is it mechanically executable)
[18:12:46] jang
closest bri has are attribute grammars
[18:12:54] jang
danbri: schematron is the closest I've seen
* AaronSw (informally) proposes XSLT
[18:13:14] jang
db: uneasy about it's completeness
[18:13:33] jang
restating question about transformation:
[18:13:44] jang
rdfxml must be translated by a parser into some representation of the graph
[18:14:02] jang
is there a way of describing this transformation mechanically and executably?
[18:14:13] jang
SM: there's a new parser that uses javacc
[18:14:25] jang
javacc ives you the grammar definition
[18:14:35] jang
you can introduce bits of code into the grammar it uses
[18:14:51] jang
bri: that's basically an attribute grammar with java as the attributions
[18:15:05] jang
danbri: we sould note xslt has been used for this
[18:15:21] jang
bri: tried it, it was very large, not a good way of descibing the transformation to an implementor
[18:15:30] jang
danc has also got an xslt parser, danbri knows of another
[18:15:35] jang
(can't remember who by)
[18:15:52] jang
bri: wants a compact gramamr that can be transformed into xslt, for instance
[18:15:57] jang
danbri: that's what schematron does.
[18:16:06] jang
bri: talks about jeremy's parser
[18:16:25] jang
he had the problems due to M+S talking about characters.
[18:16:26] danbri
the other rdf xslt parser was by jason diamond
[18:16:33] jang
so he did javacc with a grammar in terms of SAX events
[18:16:48] jang
this is pretty handy
[18:17:05] jang
dave's looking for suggestions; he's stil inthe investigation phase
[18:17:15] danbri
xslt parsers: see http://www.xmlhack.com/read.php?item=757
[18:17:34] jang
art: is the WG constrained to using w3c or other standard?
[18:17:44] jang
are we bound to standardised mechanisms?
[18:18:12] jang
em: i don't think so. We must be able to represent the grammar in something that's as familiar as possible to the other xml techs
[18:18:33] jang
em: likes XDuce; but if it's one of equals he'd prefer sometng else
[18:18:39] jang
dan: relaxng looks promising too
[18:19:03] jang
danri: if we want others to have a good look at our spec, we should extend them the same courtesy
[18:19:23] jang
em: only a few people from, eg, DC will be interested in reading the spec?
[18:19:33] danbri
(re politeness: specifically within the w3c xml family of specs)
[18:19:35] jang
daveb: we want a single normative mechanism
[18:19:46] jang
em: ebnf, for example.
[18:19:54] jang
daveb: it's basically in terms of characters
[18:20:06] jang
sm: can xslt produce non-xml docuemnts?
[18:20:08] jang
all: yes
[18:20:35] jang
sm: asks for smple syntax
[18:20:45] jang
dave: we've got ntriples, that's what we've been using
[18:21:03] jang
sm: what about dealing with reification, literls, etc.? it's going to keep growing
[18:21:23] jang
brian: is ntriple broken? do we anticipate it stopping working?
[18:21:34] jang
ph: the only possible problem is scoping, i think we've resolved that
[18:21:46] jang
bri: then we stick with ntriple until it's demonstrated that it's broken
[18:22:12] jang
jang volounteers to help dave with the investigation
[18:22:19] jang
dave asks: can we include jeremy?
[18:22:25] jang
art: also interested
[18:22:32] jang
brian: AP! ask jeremy about this
[18:22:42] jang
dan: suggests schematron to invesigate
[18:22:59] jang
AP: ang, dave, art to investigate and come back with a reccommendation
[18:23:16] jang
Graham: let's be absolutely clear wat we consider the primary audience?
[18:23:40] jang
graham: i ask because XSLT exists and may be very good, but it is probably not very good at expressing the concepts to a human reader
[18:23:48] jang
is the human developer the primay audience?
[18:23:50] jang
bri: yes
[18:24:02] jang
sm: s ntriple going to be xmlised?
[18:24:05] jang
bri: no plans yet
[18:24:12] jang
sm: then we can't use xslt?
[18:24:21] jang
al: no, it can produce anything including text files
[18:24:30] jang
em: it can do tree transforms to text
[18:24:40] jang
steveP: what is the role of the ntriples syntax?
[18:24:46] jang
normative or for testing?
[18:24:54] jang
I'd be opposed (I think) to it being normative
[18:25:13] jang
bri: we need a way to represent the graph. we have to be able to write down the graph transformation
[18:25:20] jang
bri: in mymind, ntriples is for that
[18:25:24] jang
steve: but it's not a graph
[18:25:37] jang
ph: we could draw pictures in the spec
[18:25:54] jang
we need ntriples for testing, not for the defintiion
[18:26:11] jang
brian: I need some way of writing down my test-cases
[18:26:25] jang
I'd rather use one representation of a gaph
[18:26:30] jang
graph, even
[18:26:56] jang
dave: we've got a mixture of text and formalisms at the moment
[18:27:04] jang
ph: software exists to construct and transmit graphs.
[18:27:23] jang
ph: wy don't we make the exposition in the definitive document conform to the graph directly?
[18:27:40] jang
every time a graph is pictures, we can give the ntriples representation
[18:28:02] jang
danbri: i aree largely, but I'd be concerned if we say all sorts of wooly non-normative thngs about ntriples
[18:28:08] jang
it's as normative as the rest of the spec
[18:28:28] jang
ph: I was responding to brian's desire that ntriples be the way graphs are described
[18:29:19] jang
fm: one role ntriple could play in the exposition is to illustrate some of th epotential misunderstandings they may experience
[18:29:47] jang
people have been sending ntriple-ish stuff back and forward for disambiguation by email
[18:29:57] jang
so ntriples could be used as an example of a serialisation
* danbri agrees
[18:30:08] jang
to make the point that the graph model is the central issue
[18:30:32] jang
brian: when I think of ntriple, i think it behaves exatly like a graph
[18:30:46] jang
ph: all the issues of name scoping have not been properly articulated
[18:31:09] jang
graham: the advantage of using graphs directly: it'll prevent opthers from falling into the same mental trap
[18:31:32] jang
em: we've been trynig to do this for 4 years, unsuccessfully: saying "it's the graph stupid"
[18:31:46] jang
people understand the serialisation more than the abstract notion
[18:31:53] DanCon
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[18:31:54] jang
ora: I don't think that's true.
[18:32:19] jang
people see the serialisation and don't understand it represents a graph
[18:32:28] jang
em: eg,xml people see it as an xml document
[18:32:50] jang
graham: we should do everything twice in the document: once as a graph and once as ntriples
[18:33:17] jang
ora: in some sense, choosing xml was a mistake. people see xml and consider it to be just xml, not a graph
[18:33:38] jang
every time i speak about the graph, people get it though. I've stopped talking about xml and people just get it
[18:33:46] jang
em: I've seen exacty the opposite
[18:34:03] jang
people ask, "but what does it look like?" meaning, where are the angle-brackets
[18:34:41] jang
em: people are deploying a lot of apps that just happen to be rdf-friendly, eg, rss - most users just consider it to be an xml document
[18:35:12] jang
dan: what are we trying to achieve? we're not trying to write the rdf tutorial or do modelling
[18:35:57] jang
we're not trying to write the tutorial here - in that context, does anyone have anything else to add?
[18:36:20] jang
mike d: we've produced another serialisation for rdf. if we play it up, won't people start using it?
[18:36:36] jang
how important is it to emphasise that the xml serialisation is the preferred syntax
[18:36:45] jang
bri: we're not chartered to develop a new synta
[18:37:00] jang
mike: it's becoming bigger. it's for test cases basically
[18:37:24] jang
ph: it sends a good messge - there are at least two maybe more serialisations of rdf
[18:37:35] jang
M+S doesn't hammer this home sufficiently
[18:37:54] jang
arno: this can create some confusion. eg, DC has multiple representations
[18:38:14] jang
documents that have different forms tend to be interpreted differently
[18:38:36] jang
em: let's not go there yet. it is non-trivial to convince people to deploy multiple syntaxes
[18:38:58] jang
ph: we either say, there is one preferred syntax, and not mention any others, or we shoud say
[18:39:06] jang
rdf is about graphs and there may be muktiple syntaxes
[18:39:24] jang
danbri: this has been very important to exaplin to people.
[18:39:50] jang
em: I want that, yes: we're building on the first M+S
[18:40:16] jang
this diagram (referring to the graph -> MT, ntriples, serialisation diagram) is really importnat
[18:40:35] jang
e: priority should be to clarify the model (graph) and focus on the rdf xml serialisation
[18:41:12] jang
ora: says "S-expressions" and gets lynched
[18:41:12] jang
brian: moving on to schema
[18:41:12] jang
minute break, back in a tick...
[18:55:51] jang
back: rdf schema issues
[18:56:00] jang
danbri to lead, brian to timekeep + chair
[18:56:15] jang
eric has noes on laptop
[18:56:21] AaronSw
[18:56:30] AaronSw
- notes
[18:56:32] jang
ap: eric/danbri to ensure dan's document goes online
[18:56:41] scribe
======== DanBri - RDFSchema ========
[18:57:57] jang
w3c think rdfsch is more or less done
[18:58:06] jang
we've had feedback... particularly from daml+oil
[18:58:36] jang
rdfschema work stopped waiting for xml schema - that's now done
[18:58:49] jang
we need to take the useful bits ( datatypes) into rdf schema
[18:59:08] shellac
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[19:00:01] jang
WG sucessor (web-ontology) is planned
[19:00:55] jang
dan points out: what we decide/do next doesn' have to be writen in stone, so we make pragmatic ecisions on what the next WD looks like
[19:01:55] jang
domain + range is an open issue; dan proposes we skip over this because there's a good answer
[19:02:19] jang
this is a no-brainer
[19:02:47] jang
ora gives a bit of background to rdfschema; we're after an OO extensible type system to rdf
[19:03:02] jang
we're after very little.
[19:03:54] jang
ora: te properties of properties are global - no class-specific constraints
[19:03:59] jang
we fixed this in daml
[19:04:17] jang
domain + range: this is the open issue
[19:05:12] jang
dan talks about daml work getting pushed into schema/web-ont - we don't know or care yet what's going to ahappen about this
[19:05:23] jang
dan: ora - class-contextualised constraints may come later
[19:05:50] jang
dan: any dissent to conjunctive interpretation of range+domain?
[19:07:04] jang
art: is there any evidence that people are using current semantics?
[19:07:07] jang
jan: I've seen some
[19:07:14] jang
AP: jan to write up the fix/workaround for this
[19:07:36] jang
ron: possible to change the namespace to not break stuff for people?
[19:07:55] jang
dan: yes, it's possible, my preferred take:
[19:08:15] jang
there is a thing called rdf:domain which the rdfschema people have previously made an erroneous statement about
[19:08:36] jang
ph: introducing a new namespace isn't always the most painful thing
[19:08:53] jang
AP: rdf schema editor to fold conjunctive decision into the raph
[19:09:53] jang
APPROVED: multiple domains, ranges, with conjunctive semantics
[19:10:01] jang
pretty much carried unanimously
[19:11:21] jang
approved by ora, brian, art, jos, dave b, martin, ph, ron d, frank m, sergei, kwon, em, arno, stephen p, jan, raham,
[19:11:31] jang
we record no objections: ron daniel abstained
[19:11:44] jang
(danbri also voted in favour)
[19:12:26] jang
rdfs:domain & rang constraingts or rdfs:domain were missing from the schema - this is just a typo
[19:12:33] jang
proposal to fix this
[19:13:17] jang
ron: was the editorial oversight due to non-discussion/ non-decision or was a decision recorded
[19:13:24] jang
but didn't make it to the doc?
[19:13:37] jang
dan: not certain; but the pictures we had show these values
[19:13:46] jang
proposal: editor to fold these into the next WD
[19:14:36] jang
all in favour, no abstentions, no against
[19:14:40] jang
[19:15:15] jang
subclassing containers...
[19:15:36] jang
dan: a compelling case for this was not allowed
[19:15:41] jang
[19:15:47] jang
for the next wd, we say: future work
[19:16:18] jang
AP: jan to provide explanation of how we'd add this
[19:17:35] jang
proposal: no change on this issue in next draft of rdfs
[19:17:50] jang
we take as resolved on the issues list
[19:18:13] jang
(recording accurately the nature of the resolution)
[19:19:50] jang
all in favour: abstain frank, no against
[19:19:55] jang
[19:20:34] jang
[19:21:56] jang
ron: originally we discussed this and decided to wait for xml:schema
[19:22:12] jang
proposal is to take in what DAML+OIL did, throw it in and then argue abot ti later
* GK-f2f INFO: CC/PP uses XML schema datatypes - http://www.w3.org/TR/CCPP-struct-vocab/
[19:22:41] jang
this sin't for the next WD, just as the next step
[19:23:11] jang
proposal (refined)
[19:23:25] jang
we expect to work in this area, informed by the daml+oil work
[19:25:41] jang
AP: graham to send to working group how CCPP does datatypes
[19:26:01] jang
AP: ajn to do the same with the EASEL approach
[19:26:20] jang
ora: the daml+oil approach is clever because if you don't care, you don't get hurt
[19:26:49] jang
proposal: to go away and investigate and report back to the group
[19:27:00] jang
dan: taskforce to consider the adoption of...
[19:27:43] jang
adopt daml+oil/xml datatypes as initial foray into the issue
[19:27:55] jang
we don't consider closure on this issue a must-have for the next WD
[19:28:18] jang
drop the "adopt"
[19:28:30] jang
final proposal should come from EM's document, he's editing it now
[19:29:22] jang
volounteers: danbri graham, martin, jan
[19:30:15] jang
all in favour of the taskgroup
[19:32:10] jang
brian leaves to order pizza
[19:33:48] jang
[19:36:28] jang
AP: pat to go into some more detail on why the know-tying at the top of the hierarchy in rdfs is not a set-theoretical hole
[19:37:14] shellac
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[19:37:20] jang
[19:38:04] jang
proposal: we don't think this is a problem
[19:38:32] jang
so we close the issue, with the expositional urden associated
* GK-f2f INFO: Horrocks, et al paper is at http://www.semanticweb.org/SWWS/program/full/paper40.pdf
[19:40:20] jang
dan explains how we go around answering this (process issues)
[19:40:30] jang
we're obliged to respond to feedback
* GK-f2f Last URI was wrong one ... still looking
[19:41:42] jang
all in favour. no abstain, no against (brian absent)
[19:41:59] jang
cycles in subclassof
* GK-f2f I think this is the right one: http://www.semanticweb.org/SWWS/program/full/paper11.pdf
[19:42:36] jang
daml+oil didn't like this
[19:42:58] jang
dan: personal bias towards what we've got is a bad usability problem explaining it to people
[19:43:25] jang
graham: one reason to change is that this is one of those things that can't be described within the schema framework
[19:43:27] jang
thus we drop it
[19:43:46] jang
ora: doesn'tcare
[19:44:05] jang
dave: biggest implementation in this area doing this already? will we break something?
[19:44:17] jang
dan: opens floodgates
[19:44:34] jang
ron: recalls experience was that people wouldn't want cycles in te subgraph relationship
[19:45:00] jang
this will break a lot of implementations if we use this. in particular, stuff out there won't be doing cycle detection
[19:45:12] jang
danbri: the system is gullible if it's not checking this restriction
[19:45:33] jang
ron: no, that's not fair - if the spec tells you there are no cycles, then there is a performance optimisationto not bother checking
[19:46:01] jang
frank: that argument can be ade for any syntactic description. this is absurd if taken to its extreme conclusion
[19:46:20] jang
dan: I was going to ask someone from DAML how strongly they care
[19:46:36] jang
graham: we need to make the change ASAP if we're going to hurt as few people as possible
[19:47:11] jang
dave: rather than do nothing, I want to know now what we're doing, are we gogin
[19:47:17] jang
to change it
[19:47:51] jang
PH recalls why daml people wanted this - it was fought hard over
[19:48:01] jang
ora: frank + ian do class equality doing this
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[19:48:10] jang
which frees them from having another relationship
[19:48:16] jang
and that this is DL accepted practice
[19:48:58] jang
frank: I did circulate a paper sumarising the major arguments for this change from DAML
[19:49:11] jang
people are going to write these; what do we want to happen?
[19:49:56] jang
do we barf, notice this, flag it up as a possible problem, etc?
[19:50:11] jang
frank: there are a number of large-scale ontologies with cycles.
[19:50:52] jang
PH: the critical case for DAML+OIL thinking was that subsetting relationship might be made by multiple people
[19:51:12] jang
the logical conclusion is that the two classes are co-extensive
[19:51:47] jang
PH: the issue is, is subclassof lessthan or lessthanorequal
[19:52:00] jang
one has cycles, one doesn't; we really need both
[19:52:34] jang
EM: when merging large ontologies, we can't prohibit cycles from happening
[19:52:40] jang
the issue is, what does it mean? (PH)
[19:53:09] jang
this is the only place where two ontologies could contradict each oter (in rdf + rdfs)
[19:53:20] jang
dan tries to close this
[19:53:37] jang
can we resolve that people who care about this go away and come back with some advice?
[19:53:56] jang
ron would like a vote
[19:54:14] jang
brian returns at this point.
[19:55:09] jang
em: options: taskforce, or discuss now (useful)
[19:55:18] jang
ron: third option: strawpoll?
[19:57:23] jang
dave: programmers from OO languages dont like this
[19:58:27] jang
non-binding strawpoll
[19:58:45] jang
insufficient consensus on this
[19:58:54] jang
dan stresses we're only talking about the next WD
[19:59:52] jang
sergei says why he's against (because of dave's point)
[20:00:58] jang
ron: suggests we record this that we insert a question into the next WD
[20:01:04] jang
asking for feedback
[20:01:10] jang
this now becomes the proposal....
[20:01:23] jang
ORA: AP - talk to ian +frank t get the background on this
[20:02:55] jang
proposal: we stick something in the WD saying "we're looking for feedback - we're going to pull this - how badly does it hurt?"
[20:03:11] jang
PH: daml will invent daml:subclassof f you don't take this out
[20:03:44] jang
frank: the daml+OIL people gave us explicit feedback, which strongly mentioned this
[20:04:27] jang
frank: also want explicitly recognised that frank sent the feedback t the WG list
[20:04:41] jang
this shouldn't be news to us we HAVE feedback already!)
[20:05:36] jang
ron: by nserting this in the document then this becomes a resonse to the DAML+OIL people
[20:05:44] jang
PH: that sounds perfectly fine
[20:06:09] jang
jos: we're discussing subpropertyof too
[20:06:23] jang
danbri: yes, we take this to be the case
[20:06:45] jang
can frank modify his document into something to put in the next WD?
[20:07:30] jang
em: propose flaed in the next draft
[20:07:48] jang
also: someone (frank) to go back to the DAML+OIL people and ask for moe convincing arguments
[20:08:21] jang
AP: pat to take this back to the DAML people at the next telecon and bring the feedback to us
[20:09:02] jang
summary: OO programmers are confused, people are trying to code-generate classes (java) for this
[20:09:06] jang
thus we have to go back
[20:09:39] jang
proposal: open the issue, take the stuff to DAML (PH) and continue the discussion
* AaronSw (informally) notes java doesn't even have multiple inheritance, so it's not really a good example
[20:10:08] jang
frank to own this issue.
[20:10:22] jang
aaron: it has multiple inheritance of interfaces
[20:10:30] jang
(after a particular fashion)
[20:10:38] jang
not of implementations
* AaronSw scrunches his face up...well, yeah
* GK-f2f Java no MI of classes, true, but it does have MI iknterfaces
* AaronSw notes (informally) that python allows inheritance cycles
[20:12:30] jang
propose: open issue (frank owns ) plus PH, ora to take back to DAML any feedback from this
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[20:50:25] jang
back after lunch
[20:50:47] jang
plan: finish schema, open mike
[20:50:51] jang
[20:51:25] jang
spo semantics (inheritance)
[20:51:35] jang
inheritance of range+domanin
[20:51:48] jang
seem to have fixed a lot of this with range & domain
[20:53:16] jang
jan: subproperties should inherit conjunctively the range+domain of their superproperties
[20:53:24] jang
ron: is there a clarification that's been asked for?
[20:54:48] jang
general agreement with jan's statement of this
[20:55:24] jang
AP: dan clarify prose to reflect this position accurately
[20:56:03] jang
then issue closes
[20:56:30] jang
subclass of a subproperty
[20:56:40] jang
(previous issue RESOLVED)
[20:57:30] jang
are rdfs:Class and rdfs:Property disjoint?
[20:57:45] jang
ora has seen an instanc of this
[20:57:58] jang
didn't see any reason why this shouldn't be permitted
[20:58:28] jang
dan talks about rss:image
[20:58:47] jang
PH: the real question is "what does this mean?"
[20:59:15] jang
em: finds it very confusing
[20:59:41] jang
dan: default thing is to do nothing; the spec's silent on this
[20:59:56] jang
dan's candidate meaning is "coincidence" - ph's MT does this
[21:00:44] jang
proposal: can we restate this as "are Property and Class disjoint?"
[21:01:07] jang
the proposal is to record this issue in this style
[21:01:54] jang
and to do nothing in the next WD
[21:03:56] jang
we move on
* barstow_ notes to GK that MIT [thus W3C] is experiencing network problems ...
[21:04:37] jang
(this is our resolution)
[21:04:52] jang
onlie char encoding
[21:05:12] jang
proposal: editor to fix this
[21:05:16] jang
[21:05:25] jang
(we don't want to rathole on this nobrainer)
[21:05:30] jang
[21:05:36] jang
known and had problem
[21:05:40] jang
[21:05:59] jang
this is very very difficult. Nobody really appears to know how to do this. Open research issue
* AaronSw doesn't think so
[21:06:41] jang
Proposal: note this is very hard, close the issue.
[21:07:30] jang
PH: proposal "wepropose to not answer this!"
[21:07:57] jang
in other words, we leave the spec as it is
* AaronSw is vehemently opposed to that proposal
[21:08:15] jang
moving on
[21:08:22] jang
you're not here; take it to email
[21:08:49] jang
transitive subproperty
[21:09:35] GK-f2f
Jan: Counter-example sisterOf subproperty of siblingOf
[21:09:50] jang
proposal: the answer is "no" it's not transitive
[21:10:13] jang
AP on anyone who cares: find an explanatory piece of prose on this
[21:10:17] jang
AP on JAN to do this
[21:10:41] jang
AP on editor: chase jan on this
[21:12:32] jang
movin on
[21:12:46] jang
(ron notes that he's not convinced in this case)
[21:12:56] jang
we make no changes to the next draft; this issue remains open
[21:13:33] jang
we do that. frank, steve P abstain
[21:13:37] jang
[21:13:44] jang
subclassof and instance clarification
[21:16:03] jang
frank: we must ensure that we consider the original email messages, not a summary of the issues
[21:17:08] jang
that and the next two issues (isDefinedBy semantics and editorial)
[21:17:28] jang
no action on tehse before the next WD
[21:17:44] jang
carried; a couple of abstentions (jan, steve P)
[21:19:08] jang
we leave these until later
[21:22:44] jang
new WD in one month
[21:22:44] jang
new WD of rdfs due on september sixth
[21:24:16] jang
jan notes he has acounterexample to the transitive subproperty of subproperty question
[21:29:58] jang
we go on to "where next"?
[21:30:05] jang
schema new WD by sept 6
[21:30:17] jang
syntax: we have a taskforce
[21:30:27] jang
model: pat has an action on him
[21:30:45] jang
also: second half - sergei's mechanisms for implication analysis
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[21:32:01] jang
ron especialy points out that splitting is not a requirement, merely something to consider
[21:33:04] jang
steve p asks : can we actually get a proposal out of this?
[21:34:01] jang
PH; two pieces of rdf are identical iff they map to the same graph
[21:35:23] jang
[21:36:02] jang
two rdf documents are equivalent iff they map to teh same RDF graph
[21:37:41] jang
two rdf graphs are the same when :
[21:37:51] jang
1. they are graph isomorphic
[21:38:03] jang
2. no two nodes are labelled with the same URI
* AaronSw doesn't get point 2 at all
* GK-f2f stuff on graph theory at: http://www.math.fau.edu/locke/graphthe.htm
[21:44:14] jang
we can't specify this precisely
[21:44:14] jang
so we agree that this needs more thinking about
[21:44:14] jang
we HAVE agreed that the graph is the central idea to RDF
* GK-f2f see in particular 1st para of http://www.math.fau.edu/locke/graphmat.htm
[21:45:46] jang
ron: the graph is the central concept for RDF, there are multiple graphs
[21:46:15] jang
ron reads out a whole bunch of statements that indicate we need to think
[21:46:22] jang
AP: ron to send this to the list
[21:47:01] jang
frank: as a matter of exposition, the graph model is central and the other representations are to be interpreted n that light
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* AaronSw knows what isomorphism is... not sure why RDF needs a special requrement though
[21:47:11] jang
the current text doesn't really make this clear throughout
[21:47:53] jang
in the course of making these points, we have to be careful that the message is carried throughout the whole document
[21:48:26] jang
brian: agrees; we're lookig fora rewrite, not an editing job.
[21:50:00] jang
we look at te schedule
[21:50:34] jang
we're running a lttle behind :-)
[21:51:10] jang
are there better notions of what revised dates we should commit to?
[21:51:30] jang
em: we should discuss what our delivrables are
[21:51:38] jang
we know one:rdfs, we have a date
[21:52:08] jang
re: pat's attempts aove: jang greed they had the same logical entailment, but that that was not where teh anon node issue lied
[21:52:14] jang
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[21:53:57] jang
we ask how many people would be interested in focussing on a document
* AaronSw signals agreement
[21:55:05] jang
if we had to pick to each of:
[21:55:11] jang
primer, model, df/xml, schema
[21:55:20] jang
which would they be?
[21:55:41] jang
we add "test case repository" as a deliverable
[21:56:48] jang
interested in primer: 5
[21:56:57] jang
model: 8
[21:57:07] jang
syntaxL 4
[21:57:13] jang
schema: 4
* AaronSw volunteers for primer
[21:57:22] jang
test cases: 2
[21:57:45] danbri
aaron/primer: :)
[21:58:32] jang
AP; (repeated) action item to get rdfs done
[21:58:43] jang
some of these depend on pats revised model
[22:00:19] jang
danri: we can get the telecon bridge available at other times too
[22:01:59] jang
ora: are we issuing a version of the existing spec or a new spec?
[22:02:37] jang
as comparison, there is a new XML spec.
[22:03:24] jang
ora notes that we tried to originally eparate model and syntax, and it was too hard
[22:03:49] jang
pat: is the document primarily definitive or understandable?
[22:04:57] jang
em/ora: why we smushed the documents together originally
[22:05:18] jang
we were looking for primer and spec and al sort of things
[22:05:32] jang
dave: document format is to be left ntil much later, let's produce the pieces first
[22:07:13] jang
ow many people are interested in being the editor/document layout person
[22:07:14] jang
graham is
[22:07:38] danbri
danbri is
[22:07:51] jang
graham: i sense there's significant support for the idea that model and syntax be separated
* AaronSw is interested in nitpicking
[22:08:06] danbri
(danbri is...interested in being on any group working on document partitioning)
[22:08:21] jang
good, but people are talking - I'm not going to butt in with this one (to email, you'll not be left out)
[22:08:56] jang
dave:do we need coordination?
[22:09:13] jang
em: yes, really. I'm looking for where this can take place/be centered
[22:09:23] jang
[22:09:58] jang
ron: proposal to identify a team leader for each of the items, including overall documen structure
[22:10:06] jang
this is har work, but I think that's what we need
[22:10:57] GK-f2f
brian M suggests pick a leader for the overall breakdown, and defer selecting others
[22:11:40] jang
brian proposes to take the document leader job - it's the chair's jo
[22:11:44] jang
hear, hears
[22:12:02] jang
that is document structure ONLY
[22:12:21] jang
AP: brian to take the list of sections and come back with something more cocrete to look for volounteers
[22:12:55] jang
frank: could we consider structuring theseas web things instead of PODs?
[22:13:06] jang
there, we close.
* GK-f2f I think the docs should be printable as PODs if required
[22:13:42] jang
reopen: schedule rearrangement
* GK-f2f (POD = plain old document?)
[22:13:45] jang
[22:14:13] jang
brian thinks that www11 would be a good place to annonce rec
* AaronSw thinks web things == goodness
[22:14:35] jang
hard narrative stuff and hard to print out to read onthe plane :-)
[22:14:58] jang
www11 is in may 2002
* AaronSw thinks web things != no print version
* GK-f2f yes, but I woukld want it to be a single printable doc, not lots of separate web "pages"
* AaronSw thinks that this is what XML is for -- one XML document can be distributed in multiple versions
* AaronSw also likes one-document specs, FWIW
[22:18:30] jang
AGREED: to announce REC at www2002
[22:18:35] jang
(or aim for that)
[22:19:23] jang
kwon's presentations
[22:19:23] jang
AP: kwon to get this on the web
[22:22:30] danbri
(hmm... agreed: We would really really like to announce REC at www2002...)
[22:25:46] jang
kwon's questions....
[22:25:55] jang
(from last side)
[22:26:10] jang
PH: rdf useful within machines for storing metadata
[22:26:21] jang
is this an "in" for getting RDF involved?
[22:26:54] jang
kwon's wg chair wants to go with rdf
[22:27:00] jang
but they're suffering from tool availablility
[22:27:25] jang
metametadata storage is still currently hard, esp. with rdfs in its current state
[22:27:39] jang
em: lots of people are squeamish because rdfs is not a rec
[22:28:05] jang
em: thus I'd really like to get rdfs out the door asap
[22:28:28] jang
ph: it's startling that ean entire country waiting for us to make up our minds
[22:28:49] jang
em: there are now 6 countries that have mandated DC metadata in xml/rdf in all govt produced documents
[22:29:12] jang
so the frivolous question of pat's is actually very accurate
[22:29:29] jang
dan: people see us getting interested in AI/KR issues, theyr'e worried by this
[22:29:44] jang
ron: "are we supporting the austrailian DC standard?"
[22:29:50] jang
we get these issues all the time
[22:30:06] jang
em: yes, a lot of tese people are simply waiting on a REC
[22:30:52] jang
(now dajobe scribe)
[22:31:03] jang
arnot - adobe
[22:31:14] jang
... toolkit and specification now available
[22:31:21] jang
... invite anyone interested to join program
[22:31:45] jang
... c++ and source available under an open license, probably open source
[22:32:05] jang
bwm: to kwan
[22:32:12] jang
[22:32:42] jang
... toolkits - redland, raptor by daveb, rdf api - sergey, jena - bwm
[22:32:52] jang
... cslisp - ora, kinda-perl - dan
[22:33:00] jang
... help available, please ask
[22:33:13] jang
jang is now known as dajobe
[22:33:39] dajobe
rond: demo
[22:33:56] dajobe
... presentation to time
[22:34:47] danbri
aside, danbri's perl rdf stuff: http://ilrt.org/discovery/2001/06/rdfperl/
[22:34:50] dajobe
... visual maps
[22:35:01] dajobe
... tim bray's antarti.ca
[22:35:27] dajobe
... demo contains interwoven-generated time info
[22:35:37] shellac
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[22:36:02] dajobe
... stories visualised in map form
[22:36:17] dajobe
... number of articles is area
[22:36:27] dajobe
... 'importance' by how titles are visualised
[22:36:44] dajobe
.... separate view on content using SIC codes
[22:37:27] dajobe
... example of rdf 'stuff' sent off to a different company, made into a demo
[22:37:46] dajobe
em: can you make this public?
[22:37:48] dajobe
rond: have to see
[22:39:08] dajobe
dajobe: maps.net taken rdf from dmoz too
[22:39:17] dajobe
em: short turnaround, fantastic story
[22:39:41] dajobe
[22:40:13] dajobe
em: until I got tools that knew daml+oil, did it dawn to me what daml+oil was up to
[22:40:27] dajobe
... workflow for w3c was really interesting with model and merging, equilvanentTo
[22:40:29] II
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[22:41:04] dajobe
phayes: simple stuff in daml+oil has biggest bang-for-buck
[22:41:18] dajobe
... which is what we find. Nobody much uses the advanced stuff
[22:42:05] dajobe
emiller giving w3 demo
[22:42:45] dajobe
wg chair visualising
[22:43:00] dajobe
... object of type 'chair', make it a square ...
[22:43:26] dajobe
.. chairs really don't know the unique ID of WG and don't care
[22:43:41] dajobe
... but know name and its email address etc
[22:44:07] dajobe
... tere is no unique ID for wg
[22:44:18] dajobe
... some may use homepage, email address or charter (danbri)
[22:44:23] dajobe
... and all of those are OK
[22:44:49] dajobe
... don't want to impose new requirements, but let them describe as they see them
[22:44:56] dajobe
... and ground in what they know
[22:45:19] dajobe
[22:45:30] dajobe
(url typed by hand)
[22:46:04] dajobe
.. people waned to know announcements by activity eg.. everyting by XML activity
[22:46:04] dajobe
... and the WG chairs don't need to add this
[22:46:19] dajobe
... people who describe activity structure have different anmes than the chairs do for wgS
[22:46:27] dajobe
... they can make their descriptions in a different way
[22:46:48] dajobe
... so long as they agree on the id for the entity, they can merge (e.g. mail addr)
[22:47:08] dajobe
... so without the notion of the contact:mailbox as daml:equilalent we couldn't merge
[22:47:20] dajobe
... so need daml peroperties to do this
[22:47:38] dajobe
... interesting to see how processing this info wtih different levels of tools became a powerful thing
[22:47:55] dajobe
... and these things can be incremenetly layered. Int his case I needed damil:equiv
[22:48:00] dajobe
... but in other forms, I didn't
[22:48:07] dajobe
(slide 39-1.html)
[22:48:35] dajobe
... some get merged because of unique ids, some from daml:equivalent too
[22:49:07] dajobe
... we can do this by graph merging mostly and sometimes need daml
[22:49:21] dajobe
... incrementaly layering functionality
[22:49:30] dajobe
... greate experience to get hands on the tools for this
[22:49:43] dajobe
... and sometimes we realise we can weave into the workflow assigning unique ids for these
[22:50:00] dajobe
... lwo hanging fruit for daml is uniqueproperty, damlequivalent, ... (lost 3rd)
[22:50:13] dajobe
... very powerful
[22:50:34] dajobe
3rd was daml:unambiguous
[22:50:56] dajobe
[22:51:12] dajobe
ora: was mandated in daml program for all participants to use daml on their pages
[22:51:31] dajobe
... if you looked at the feature usage, most people just used rdf schema, very few daml bits
[22:51:52] dajobe
phayes: if you looka t daml+oil working at daml reseacher level
[22:51:53] dajobe
[22:52:06] dajobe
... they are running into limitations of daml+oil
[22:52:17] dajobe
... and hence has divergent pulls to simplicity, complexity
[22:52:26] dajobe
danbri: I've run into those concernts, more of a spectrum
[22:53:01] dajobe
... data merging is critical, before daml I had something monoproperty. daml properties don't license all the merging done in em's demo
[22:53:10] dajobe
monoproperty was 'same for all time'
[22:53:18] dajobe
em: rdf notion of layering
[22:53:29] dajobe
... daml may require more layers, but if done in this way, remains useful and power
[22:53:38] dajobe
danbri: sw-cg job is to get thesecharters layered
[22:53:48] dajobe
[22:54:10] dajobe
phayes: what this community needs is a combination of things from KR ...
[22:54:20] dajobe
... GOFK(???) ...
[22:54:30] dajobe
... some features that are pathetical easy from 1956 or something
[22:54:39] dajobe
... and some things so hard we put them off ...
[22:54:49] dajobe
... "full temporal sensitivity in changing worlds" ...
[22:54:58] dajobe
... exciting ...
[22:55:07] dajobe
... redirecting our attention to problems we put off
[22:55:21] dajobe
... and can't put off to the next millenium. Must do now, or yesterday.
[22:55:29] dajobe
bwm: pat is excited!
[22:55:34] dajobe
... wrap up
[22:55:38] dajobe
... thanks to everyone
[22:55:45] dajobe
thanks to brian
* dajobe claps
[22:55:54] dajobe
thanks scribes
[22:56:03] dajobe
more free gifts...
* AaronSw claps, grabs free gifts
[22:56:14] dajobe
XML schema f- the guide to w3c xml schema
[22:56:20] dajobe
[22:56:25] dajobe
DONM - months away :-)
[22:56:30] jimH-lurk
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[22:56:50] dajobe
AaronSw: will try to grab one for you. mostly xml.com articles in a book
[22:56:54] GK-f2f
Yes, done!!!!
[22:57:04] AaronSw
thanks, dajobe
[22:57:10] AaronSw
Good work everyone!
[22:57:35] dajobe
logger here will be closing shortly... over to #rdfig
[22:57:39] GK-f2f
I think the acronym above was GOFAI
[22:57:54] GK-f2f
(Good Old Fashioned AI)
[22:58:00] AaronSw
[22:58:13] barstow_
barstow_ has left channel

Provided by Dave Beckett, Institute for Learning and Research Technology, University of Bristol