See also: IRC log
csma: Mar 8 will be the new deadline of
the UCR document then WG review
and we will vote on 14 Mar
...just the UC section
...questions?
...Now get to the use cases ...
Chris:Marla's comment is the same
...Any discussion of the use case?
csma: some concern similar to the 2.5 Human-oriented Business
Rules
Allen:
it could be, but this is natural use case for
...but I am not sure it is similar
...any device can have mistake, ... I don't know whether
we should label it as compliant
csma: then seems that they are different use cases
Allen: it is a very broad area and RIF will be very useful
Chris: any more comments?
UC is approved
Chris: marla has the same comment?
OK
discussion ...
Sandro: I don't understand the section, I see only OWL ++
csma: My understanding is it is not only
extension of OWL ...
...the point is the rules are needed to be part of the
vocabulary
Paul: are there any existing rule extension of OWL?
Chris: there are
csma: I used OWL as a justification
Francois: My suggestion is to make the RIF language extremely expressive
csma: does it make sense to put the uncle example with the brain one
Christin: the brain one is a real example and the uncle one is not
Sandro: I think we need a real one
Gavin: we need some text to show the connection between OWL and RIF
<scribe> ACTION: Francois to contact Ian about the change of the use case [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action01]
Chris: Michael, can you explain your comments?
Michael: I think the big picture of the section is fine but we should make it simple for readers to read
Chris: do you have any specific comments on change?
<scribe> ACTION: Michael to provide some specific comments of 2.8 [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action02]
Michael: maybe we should extend the use case and make it more general
Sandro: ...
Chris: [summarise what Sandro said] We
should change the name, existence of OWL is a justification of the need
of exchange ontologies
...Proposed new name: Interchanging extended ontologies because there
are no standard to cover that
Francois: it seems too technical and I would like to see the applicataion in the title
A main title about the application field, and a technical sub-title
Sandro: sounds like a good idea
Christine: I think the application title
is too narrow, what about "compatability between ontologies and rules"
...this is required by many use cases in many different
field
Sandro: OK I see the point
Sandro propose: Interchaning rule extensions to ontology languages
Chris: do we need to consider languages
outside W3C standards?
...any languages?
csma: topic map
pfps: CYC-L
csma: common logic too, although it is not an ontology language and more like a rule language
Sandro: what aout "Interchaning rule
extensions to RDF and OWL"
Don: What about mismatches between source
and
target
systems?
Chris:
That is a different use case.
...Title: Interchanging Rule Extensions to OWL (for
Brain Anatomy Research)
...Rationale:
That is the use case.
?:
Does this cover RDF?
Chris:
No, should it be covered?
Jeremy:
No, this use case is adequate (for HP).
?:
This loses the idea of rich ontology languages.
Chris:
This would be a new use case.
Michael:
Leave the qualifier off the title, to allow for
other examples.
Francois:
The qualifier is a good title - it says it
all.
...Titles need to be concrete.
Chris:
Objections to the title?
Giorgos
Stamou: The use is general, the example is just
illustrative.
Chris:
Title options 1/ no clause 2/ "for"
clause 3/ subtitle
...Title: Interchanging Rule Extensions to OWL - A Brain Anatomy Research Example
...Actions 1/ remove uncle example and replace with
brain anatomy example
...2/ make title be Interchanging rule
extensions to OWL
ACTION on PFPS
- ask Ian to make changes to use case
Chris
and Michael: modify Michael's action to think about
new, related use case
Sandro: Right thing is to have Frank revise to address concerns
?:
Perhaps the right thing is to have 2 use
cases
Christian: New topic is "process and supply
chain"
?: Perhaps might integrate remaining part of 2.6
Sandro: New title is "access to business rules
of
supply chain partners"
Frank: 2.6 example is FOAF-style rules about
telephone
contact rules
Christian: Proposal 1: remaining part of 2.6
fits into
2.1, so 2.6 is deleted
...Proposal 2: remove data
integration from
2.1, retitle, and revise, ensuring
that there are rules there
...Proposal 3: add new use
case about data
integration
Sandro: moving 2.6 to 2.1 doesn't make sense
Christian: ok
Chris: objections to Proposal 2?
Sandro: I can take the stuff from the charter
and make it
into use case 2.9
...Title:
Vocabulary mapping for data integration
Christian: consult with Dave Reynolds
Sergio: there should be something about
incomplete
information in the use case
Jeremy: data integration use case is
interesting to HP
because it is simple
Hassan: why is the use case related to
incomplete
information?
Sergio: there is often some sort of incomplete
information in data integration
Sandro: This is a synthetic use case - does
anyone have a
real use case?
Frank: yes, there should be lots - Fujitsu has
done this
Jeremy: let's do something that can be done
fast, let's
not try to perfect the use case now
?: production systems actually don't work on
vocabulary
mapping they work,
as
well, on data mapping
Chris: Sandro will do the use case, Sergio to
provide
input
Chris: discussion on Proposal 1
?: there is still something left in the area -
something
like distributed rule bases
Harold: the use cases in 2.6 need homes
Christian: FOAF use case ends up in 2.1
Sandro: don't see anything valuable left in 2.6
Chris: objections?
Hassan: status of Use Case titles in ToC
Chris: proposal is to do this somehow
Hassan: as long as it works out
Christian: change title to above, drop
e-learning, concentrate on
prescription part (and
extend
slightly)
Chris: Objections?
<Scribe> ACTION: JeffPan propose extension to prescription example [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action03]
discusssing UCR/Interchange of Human-oriented Business
Rules
merging with 2.6 is not an option
ChrisW: use case is not close as it stands, needs catching
better the
intention
...propose to move it for next WD round?
FrancoisB: have something about BR in first draft is crucial
CSMA: propose to keep title in first WD
...alternatively Donald to come up with new text by monday?
...text can be removed
RESOLVED
no objection
<Scribe> ACTION: JohnHall come up with new text by Monday [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action04]
proposed title: tools for managing policies and
practices in
organizations
(discussing a proposed title..)
RESOLVED:
new title "Managing inter-organizational business policies
and practices"
<Scribe> ACTION: JohnHall to reflect that title in the new proposed text [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action05]
DONE with UCR discussion!!! fireworks
Axel: proposal to
colocate with next ESWC Montenegro June 11-14
.. either 8-9 or 9-10 is
proposed
Igor:
afterconference is
not an option
...8-9 was originally
planned for RIF
...15-16
ChrisW:
No clash with KR meeting 2-5June
no objection to have next F2F Montenegro either June 8-9 or June 9-10
RESOLVED: to have next F2F Montenegro either June 8-9 or June 9-10
RESOLVED: to have WBS vote per organization
<Scribe> ACTION: Sandro to organize such WBS vote [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action06]
by next tcon have resolution on the date
<Scribe> ACTION: AxelP to set up logistics F2F page [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action07]
Christian:
The following face-to-face
should be mid September - mid November:...Submit
proposals asap...Decision at next face-to-face (
Action on
Presentation by HaroldB (slides)
Frank: Production Rules semantics are not monotonic. PR is not true subset in phase 1 - cannot characterize PR with assert and ignore retract. If PR is split from phase II, will have to undo assert - have to retract part of phase 1
(discussion about semantics of production rules)
<Scribe> ACTION: Frank to make his point on the mailing list [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action08]
Francois: need for complex 'actions' in production rules (besides complex events and complex conditions)
<Harold> Harold: can already do the syntactic extensions in Phase1
.. to make clear what might be done semantically in Phase2
<GaryHallmark> +1 on including production rules earlier
<Scribe> ACTION: Harold to explain technically the basis for interoperation between PR and Horn rules [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action09]
Uli: What are
the proposals?
Uli:
2 or 3 formalisms for
phase 2?
Uli:
What are Phase 1
semantics?
MichaelK:Phase1 is
one
semantics i.e. FOL entailment (is in response to Uli's question)
Christian
Francois
Christian
...
...
New Wiki pages
for requirements
& design goals
...Name and short
description,
annotate existing requirements where possible
...Refer to existing
...Cut off in 3 weeks
Action on
<ChrisW> mike dean, are you here?
<mdean> yes
Sandro:Previous session
of
collecting requirements is not satisfying.
... there are many rule
systems, but we need to identify common features
... there should be some
sharing among similar systems
... e.g. sharing between
several different production rulse systems
... Try to establish a
framework
csma:agrees. Identify
features that can be reused by other systems.
... provide guidance of
how
to work with unsupported features.
Chris: Highly important
to
be compatible with existing Semweb standards
... different possible
views:
... (1) OWL as a part of
(the syntax of) RIF
... OWL does not get
translated
... but is just loaded in
RIF without change
... (2) OWL is a covered/source/target language
Mala:What about other langues such as Common Logic?
Chris:OWL ist a W3C standard, so compatibility is part of the charter.
Harold:I would like to
add
a third point: (3) interoperation
... meaning that one
refers
to another (OWL) document which remains external
<josb> As I understood Harold, you include queries to OWL ontologies in the body of the rule
<Scribe> Yes, I think so
Sandro:There might be
another aspect of (1): Transforming parts of OWL (e.g. DLP) into a rule
syntax.
...Elaboration of point (2):
... * syntax/semantics of OWL
in RIF
... * mapping of OWL "Rules"
... (3) dubbed "OWL in a box"
Francois:+1 Harold (i.e. point (3) above)
Hassan:It is not the
concern of RIF to specify how to reason with encoded logical
specifications. RIF provides the semantics and those who employ RIF
must provide their operationalisation.
... It suffices to encode
OWL semantics in rules.
Francois:Syntax of
course
must be compatible or translatable -- but this is secondary.
... Reasoning is more
important.
... Reasoning for rule
languages is typically constructive.
... Which is simpler than
reasoning in other formalisms (no excluded middle, refutation, ...)
... Implementing an OWL
reasoner in RIF would not be good.
ChrisWe do not want to do this.
Francois:Translating OWL into RIF does not make sense. (?)
Harold:The expressiveness needed to translate OWL into RIF is not available in Phase 1.
Chris:Any other ideas on Semantic Web compatibility as well?
csma:Can't this be applied to RDF as well?
Harold:We probably mean OWL DL and this refers to a subset of RDF as well.
Chris: I was talking
about
OWL in general.
...What are the
options
for RDF and RDFS?
Frank:The case of
combining OWL with another rule language is important.
.. e.g. one could combine
OWL with Prolog
... and this combined
language might have a different mapping to RIF
Chris:Mapping OWL into Prolog is lossy already.
Frank:It might be possible to have non-lossy combinations.
Chris:It seems that it would then be possible to use a uniform mapping.
Francois:Rule languages
often have no disjunctive reasoning.
... and translating C
\sqsubseteq A\sqsup B might be problematic
... since a lossy
translation "A <- C" is not useful
Chris:Why should a rule language not have disjunctions in the head?
Francois:Such rule languages do not seem useful, since they might be incompatible to existing languages.
Sandro:Full FOL is in scope for Phase 2.
csma:If there is an implemented rule language that allows disjunction in the head, then we can decide on whether we want to cover these or not. We do not question the language.
<Scribe> Discussion on whether OWL syntax should be part of RIF.
Chris:This may conflict with the requirement of having a nice syntax.
Deepa:If OWL/XML is part of RIF, does every RIF-conformant processor have to support OWL?
Chris:No. This is not required, since hardly any system can be expected to support all languages captured by RIF.
Sandro:The label
"sublanguage" [used by Chris earlier] was replaced early on by the idea
of "modules" in the charter.
... So one can have
systems
conforming to some RIF module.
Sergio:Not every OWL-DL document is an RDF document. The syntactic way in which OWL-DL is defined is not very simple. Including it directly in RIF might cause unpleasant definitions of syntax.
Chris:The basic question is: should there be a "special treatment" for OWL, or is it just treated as any other language we support?
Sandro:The options (2) (a) [OWL semantics in RIF, new syntax] and (b) [OWL translated into rules, that are more expressive than Horn] are available for any language.
Francois:Theory Reasoning/Theory Resolution might also be a general option.
Hassan:This formalism was made obsolete by Constraint Programming.
Christine:What does
"greater-than-Horn expressivity" mean in point (2)(b)?
... will we end up with a
super-set approach when supporting many languages in this way?
Chris:OWL has a special status that other languages *may* not have.
Francois:We are at the
crossing point of this WG!
... Two choices:
... (i) RIF is a language
which has disjunctive rules (disjunction in heads). This has advantages
(great expressiveness), but also disadvantages: you may not find
efficient reasoners.
Sandro:There might be
more
reasoners in the future.
... It must not be our
concern at the moment.
Francois:It is still
dangerous. we might come up with things that are not supported by any
usable reasoner. It might not be realizable in practical systems.
... this is rather a
reasearch topic.
Chris:We do not require that there are reasoners for RIF.
Francois:Second approach:
... (ii) We can look
around
at best practices in Computer Science.
.. there are currently
three kinds of rules.
... Database-like rules,
Integrity constrainst, and reactive rules
... So one should look at
existing tools to find what is useful in practice.
Chris:Let us turn our findings into something concrete.
<Scribe> ACTION: Francois writes down the details of his proposal. [recorded in http://www.w3.org/2006/02/28-rif-minutes.html#action10]
Chris:Other approaches to Semweb compatibility?
PFPS:You could relax the
requirement of having "OWL/XML" as a syntactical embedding of OWL into
RIF.
... so why not admit
another syntax, such as OWL abstract syntax.
Chris:This is not an option since OWL/XML is the only syntax for OWL Full.
<Scribe> Show of hands
Chris:Who thinks (1) is the way to support OWL?
<Scribe> -> 1 person
Francois:In FOL you
often
have a placeholder for terms, whereas in OWL you leave terms implicit.
... I like both. So maybe
we can keep both options?
... you can choose either
way, or try to combine both.
... Description Logic has
another cultural style than FOL.
... There might be
problems
of combining the two.
Michael:Clarification: (1) was embedding without translation, and (2) (a) includes a new syntax for OWL?
csma:Yes.
Chris:So there a two
styles, one based on modal logic that shows not terms, the other in FOL
with explicit terms.
... but the modal syntax
can be mapped to FOL.
... So it probably not
that
hard to map one style to the other.
<Scribe> Chris provides more clarification concerning the different between (2) (a) and (b).
Chris:Who thinks that (2) (a) is the way for RIF to be compatible with OWL?
<Scribe> -> 7 people
Chris:Who thinks that (2) (b) is the way for RIF to be compatible with OWL?
<Scribe> -> 15 people
Chris:Who thinks that (3) is the way for RIF to be compatible with OWL?
<Scribe> -> 18 people
csma:In (2) (b) OWL implementers seem to have to do the work, while in (a) we seem to have to do it. That is why I prefer (b).
MichaelKNobody has to do the work.
SergioThe works by
Eiter
and Rosati are examples for (3).
... both are possible.
Igor:I had a different
undertanding of (3).
... Wasn't (3) more like
SPARQL?
Chris:No, rather not.
JosB:If you have a FOL sublanguage of RIF, then (2) is possible. But in a Logic Programming setting, you have to restrict to (3).
Chris:Any other
comments?
[none]
... Another aspect of the
compatibility discussion are URIs.
PFPS:We should use IRIs
Sandro:I think we can still say "URIs"
Chris:So to what part
are
URIs part of RIF?
...Should all our
symbols be URIs?
Francois:The URI issue
seems to be important for reasoning on the web.
... Another aspect is
privacy of data. So can we restrict RIF rules to some part of the Web?
... Something similar is
possible in RDF. There one can include statements.
[General disagreement: there is no import/include in RDF]
Sandro:URIs are used
both
as names and as locations.
... RDF never uses them
as
addresses. We have to be careful to distinguish this.
Chris:To the commercial
rule vendors:
... would it be a
limitation to have to use URIs for every symbol in RIF?
PaulV:This is just a mapping issue. No major problem.
Francois:The possibility
of hiding is very important. It might be useful for us.
... (hiding as in
Software
Engineering)
Sandro:We would need a
serious reason for supporting this.
... It seems to be
complicated.
<josb> +1
Frank:The descision that
some identifiers are the same can be complicated in some logical
systems.
... So requiring that
every
URI is a different thing affects reasoning.
Chris:E.g. in OWL this is not assumed.
Harold:more about
RDF
...bnodes, see wiki
...binary/ternary relations, ...
... mappings; correspondence of RDFS and RIF
Chris: any burning issues?
csma: major achievements: use cases ...
... design goals ...
... moving toward technical spec
... thanks the scribes :-)
... minutes as fast as possible
... reminds us of schedule
... telecon in two weeks: uc
... lots of actions
... closing statement: thanks everybody
... see you next time