SV_MEETING_TITLE -- 8 Jun 2006

<sandro> Mike, can you hear anything?

<mdean_home> yes, i can hear things intermittently

<Darko> +Darko

<sandro> (Phone seems to be working, as far as I can tell, with my VOIP connection)

<PaulV> PaulV is scribe for this session

<sandro> scribe: PaulV

F2F3 Budva now in progress

Agenda discussion

<ChrisW> mikeD, did you hear a bunch of static?

<mdean_home> why is rif muted?

<mdean_home> no

<sandro> Mike, we were hearing some noise. Feel free to unmute rif if you want to talk.

<sandro> duh

<sandro> sorry

<sandro> my brain was being backwards.

<sandro> sorry

Goals and CSF

<mdean_home> did that help?

See http://www.w3.org/2005/rules/wg/wiki/UCR/Critical_Factors_Analysis

<sandro> I don't think it was actually from you, Mike.

<sandro> (Axel fixed it some other way)

Christian is chairing session

<ChrisW> sandro is reading the goal from GCR doc

<ChrisW> document being discussed: http://www.w3.org/2005/rules/wg/wiki/UCR/Critical_Factors_Analysis

Vote who agrees on leaving goals and CSFs as are...

<sandro> strawpoll

poll: 15 agree, 1 against

<ChrisW> discussing the third goal: "compatibility with W3C standards"

Dave: another option is a goal ie a SW rule lang

<sandro> Dave: modifiy 3rd goal, or 4th goal --- "Basis for Semantic Web Rule Language"

<sandro> Dave: modifiy 3rd goal, or 4th goal --- "Basis for a Semantic Web Rule Language"

<sandro> Dave: For example -- RDF Deduction rules. Not really motivated by W3C Consistency.

Sandro: would this be covered if RIF covered existing SW rule langs?

<sandro> Sandro: Would that goal come from convering eg N3 and JenaRules?

<sandro> JosDeBruijn

Jos: support need for discussion on SW rule lang

<sandro> Dave: Sandro, people need to know which language to write rules in.

<sandro> Dave: Sandro, people need to know which language to write rules in (for the SemWeb)

Dave: reply: RIF does not solve *which lang* to choose for SWeb

<josb> RIF should recommend THE language to use for the SemWeb

<sandro> Mike, if you want to talk, you might include my name to help make sure I notice and let the chair know.

Michael: building SWeb langs requires other groups involvement...

Christian summary: option is 1 a new SW rule lang or 2 interchange with a SW rule lang

Dave: maybe a SW rule lang is not a part of RIF, but specified langs could be defined as a subgroup of RIF; RIF WG needs to be clear on SW rule lang ambitions

<sandro> DaveR: I'd like UCR to be clear that we have this ambition -- of being SemWeb Rule Language Basis

Christian: opinion: specifing SW Rule Lang is out of scope for RIF

Hassan: a SWeb rule lang needs to be RIF compliant, WHEN it is produced

Christian: if a semantic is defined as appropriate for SWeb rules, and semantic is covered in RIF, then RIF could specify this semantic (not language)

Jos: semantic = language (!)

<ChrisW> syntax&semantics = language

Sandro: (such a semantic) might not be called a "language" = small issue; problem with RIF as SW rule lang is that RIF != a single dialect

Jos: you propose a particular way to implement a SW Rule Lang - is this a RIF goal? SWeb may have other semantics...

<sandro> Sandro: Having RIF-WG recommend one selected dialect as the Semantic Web Rule Language -- would that address the need here? (Dave and Jos nod)

Christian: RIF has not been chartered to select the semantic for SW Rule Lang

Michael: dialect framework may be basis for SW rule lang requirement

Harold: could have a group discussing interchange vs human use etc; call for implementations would be different eg translators rather than execution engines

Sandro: general W3 is call for implementation (translator / executor not specified)

<sandro> Proposed Goal or CSF -- "Single dialect recommended for interchanging Semantic Web Rules" or "Recommend Semantic Web Rule Language"

<sandro> "Provide S.W.R.L" ?

Axel: Requirement is a subgoal with translators

Gary: RIF also used for exch between editors etc, eg consumer = human

<DavidHirtle> Allen's "What is a RIF and Why Create One" may be relevant for the UCR

<DavidHirtle> http://www.w3.org/2005/rules/wg/wiki/UCR/What_is_a_Rule_Interchange_Format_And_Why_Create_One

<DavidHirtle> (it was omitted in the first draft)

<AxelPolleres> PaulV: I meant: Requirement for Translators/Wrappers from to systems vs. Requirement for implementations to accept RIF natively boils down to the same thing.

Axel comment correction: I meant: Requirement for Translators/Wrappers from to systems vs. Requirement for implementations to accept RIF natively boils down to the same thing.

Jos: SW rule lang != fixed semantics; RIF in SWeb activity means RIF should be a SWeb rule lang.

Jos comment correction: SW Rule lang not necessarily a single fixed semantic

Harold: Michael's comments could be dialects for different semantics, translation via RIF: propose glossary entry for distinctions between human vs machine level etc

Hassan: agrees with Harold; no syntax in RIF, not human readable, not a language but a representation for languages

<sandro> (many disagree with Hassan)

Dave: use cases include human readable rules
... decision needed on dialects for SW rules lang

<josb> +1 to Dave!

<sandro> DaveR: spectrum:RIF will support all languages <----> one selected language

<AxelPolleres> +1 to Dave

<mdean_home> +1 to Dave

Dave: charter calls for compatibility with SWeb: do we interpret this for SW Rule Lang?

Sandro: possible 4th goal: SWeb Rule Lang; use cases need SWeb

<sandro> Sandro: Proposed 4th goal: "Support Semantic Web"

<josb> +1 to Sandro

<sandro> Sandro: but that's implied by Use Cases, I think.

Christian: computation characteristics eg features related to inference than lang are out of scope of RIF

Sandro: call for poll for 4th goal "support for SWeb"

Chris: ... but Dave asked for "SWeb rule lang"

<ChrisW> I said, "Dave has asked for a goal: the BASIS for a semantic web rule language"

Axel: Support for SemWeb and SemWeb Rule lang - these are the same...

Hassan: SWeb rule lang way out of scope / unfeasible

<sandro> (Hassan: I support goal "Support Semantic Web", but not "Foundation for Semantic Web Rule Language"

Chris: proposal needs further discussion; accepting goals does NOT preclude adding more

Christian: proposal: ACCEPT these goals NOT precluding adding new ones

<josb> so what is the use of accepting them?

<DavidHirtle> to settle on at least some

<ChrisW> Goals: Exchange of Rules, Widescale Adoption, and Consistency with W3C spec

<PaulaP> and get the UCR document ready soon :)

Dave: clarify: not ruling out vs objective for next draft?

<sandro> ChrisW: let's talk about the 4th goal more tomorrow

<sandro> (and maybe during breaks and stuff)

<scribe> ACTION: Dave to compose email of proposal for 4th goal [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action01]

<ChrisW> ACTION: DaveR to describe goal in more detail [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action02]

Poll to accept these goals ...

Objections - none

<sandro> Abstaining - FZI, DERI, JosefStefan

<sandro> DERI-Innsbruck abstaining. DERI Galway in favor.

Approve: remaining

<ChrisW> RESOLVED: Accept three goals as goals for the RIF WG

<ChrisW> break time for 30 mins

Break

RESOLUTION: accepted goals as proposed above

<break>

<AxelPolleres> scribe Axel

<AxelPolleres> scribenick AxelPolleres

Requirements

<AxelPolleres> ChrisW: Go through list discuss level of agreement, no classification yet.

<sandro> 1.a. Formal Semantics

<AxelPolleres> Paul: Examples?

<sandro> Igor: What about languages that don't have a formal semantics?

<AxelPolleres> csma: Better: waht does formal mean here?

<AxelPolleres> Piero: precise and mathematical specified.

<AxelPolleres> Gary: SQL for instance has only structured Englisch def. Should be good enough. Adjust the requirement.

<sandro> csma: When you get a ruleset through the RIF, you should get the same results everywhere, however you are using it.

<AxelPolleres> csma: Should define what it means to use the same ruleset. "formal semantics" maybe too strong

<AxelPolleres> ... are there objections against the requirement or the phrasing?

<sandro> ChrisW: When you get a ruleset in RIF, the meaning of the Ruleset will have a clear and precise semantics.

<AxelPolleres> ACTION: Paula capture proposals for rewordings for "1.1.1.a Formal Semantics" [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action03]

<sandro> Mike, do you want us to be using the Mic?

<mdean_home> that would help - thanks

<AxelPolleres> mike, can you hear us?

<mdean_home> most of the time

<sandro> 1.1.1.b

<AxelPolleres> csma: rewording proposals,e.g. "clear and precise"

1.1.1.b Interchange of rule sets will often involve different semantics ...

<sandro> Sandro: is this all-models vs minimal-model semantics?

<AxelPolleres> csma: understanding: RIF should cover exchange even if semantics is not shared.

<AxelPolleres> csma: e.g. stable model semantics vs XYZ

<Harold> If we feel that "formal" is too much to ask of certain (sub)languages of RIF (Igor: Production Rules), the term "rigorous" may be better, because it does stronger than "clear" and weaker than "formal".

<AxelPolleres> MichealK: better "different styles of semantics"

<bonatti> "formal" can be applied to certain fragments; for "operational"fragments one might resort to weaker definitions

<sandro> csma: Multple Semantics: RIF should be able to cover rule languages with different styles of semantics

<sandro> (proposal)

<AxelPolleres> Hassan: proof theoretic vs. modeltheoretic is not a discriminator, because one can coincide with the other.

<AxelPolleres> ... equally called operational vs. declarative

<AxelPolleres> Gary: for ECA production rules the best you could do would be a kind of abstract machine semantics.

<sandro> Gary: I don't want something to preclude various styles of specifying semantics

<Harold> Multiple semantics: Styles of semantics (e.g. proof-theoretic vs. model-theoretic) should be distinguished from variations of semantics (LP vs. FOL).

<AxelPolleres> csma: two axes: "ways to define semantics" and "different intended semantics"

<AxelPolleres> Jos: the first is not a difference, the second can be mutually incompatible, thus we need this requirement

<Harold> However, the variations of semantics should be done in a disciplined manner, with a well-defined characterization of the differences.

1.1.1.c Markup of semantics

<sandro> general agreement on 1.1.1b

<AxelPolleres> csma: This is equivalent with the previous one.

<AxelPolleres> ChrisW: this is a consequence from the previous two.

<sandro> Sandro: If you don't implement the semantics tag, you throw it away.

<sandro> it == the ruleset

<AxelPolleres> csma: there can be overlaps if you just discard a rule set for a different semantic "tag" e.g. full horn vs. datalog

<josb> +1 to csma: tag is solution; not requirement

<sandro> harold: the intended semantics should be reflected in the syntax

<AxelPolleres> harold: refer to charter, mentions annotations already.

<sandro> "The intended semantics of the rule set in a RIF document should be charactized syntactically"

<sandro> "identified" instead of "characterized"

<AxelPolleres> csma: 111a is clear and precise semantics, 111b is more than one, 111c is they should be "identifiable"

<sandro> "RIF should have a standard way to speify the intended semantics of the rule set in a RIF document"

<sandro> "RIF should have a standard way to specify the intended semantics of the rule set in a RIF document"

<Harold> Let's distinguish the semantics of the layers of the RIF language and the semantics of a given RIF document, which should refer to the intended layer.

<sandro> "RIF should have a standard way to identify the intended semantics of the rule set in a RIF document"

<sandro> "RIF should have a standard way to specify the semantic style of the rule set in a RIF document"

<AxelPolleres> paul: commercial languages tend to "grow", how to deal with that?

<AxelPolleres> ACTION: Paul to describe an additional requirement for evolving semantics and check whether this is already covered in "extensibility" [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action04]

<AxelPolleres> topic 1.1.1.d Meta language features

<AxelPolleres> sandro: drop this requirement.

<DavidHirtle> this doesn't fit under "Soundness"

<DavidHirtle> (probably "Coverage")

<AxelPolleres> csma: seems to be subsumed by extensibility

1.1.2 Coverage

<josb> note: meta-languages fit in extensibility, as well as coverage, according to the diagram

1.1.2a The RIF should support deduction rules

<sandro> Sandro: synonym for "Logical Rules"

<AxelPolleres> Paula: better general "logical rules"

<sandro> Piero: this is about how the rules are used -- for users. Deduction Rules means Rules that produce more information.

<AxelPolleres> piero: decuction rules vs. integrity constraints, i.e. deduction rules: produce consequences

<sandro> Sandro: this provides organization/classification for rule languages for us to cover

<sandro> "rewrite rules" ?

<AxelPolleres> Discussion: Does the requirement name specific languages or classes of rules (decuctive (FOL and LP style), normative,reactive)?

<AxelPolleres> ... to be discussed.

<Harold> The LP vs. FOL distinction could me made orthogonally to the deduction vs. normative vs. reactive distinction:

<Harold> E.g. there are LP normative rules.

1.1.2.e Combined rulesets

<AxelPolleres> 1.

<AxelPolleres> paula: previeous topic missed the requirement on "coverage of prolog style rules"

<AxelPolleres> chrisW: this is in the same bucket as the previously, back to combined rulesets

<AxelPolleres> csma: the requirement should be about combining rulesets not about combining classes of rules.

<AxelPolleres> michaelK: e.g. deductive and normative appear already in the same rulesets, e.g. in LP

<sandro> mkifer: RIF must cover rule languages which support multiple styles of rules (eg normative and deduction)

<AxelPolleres> chrisw: further discuss this one with the prevous one.

<AxelPolleres> ... (the aspect of combined rulesets which combine different types/classes of rules)

<PaulaP> +1 to Christian

<sandro> David: call this an objective

<AxelPolleres> "The RIF should support rule sets where rules are composed of features from multiple rule languages."

<josb> +1 to ChrisW: we cannot allow arbitrary combination of features

<AxelPolleres> MichealK: combination of semantics difficult to define.

<DavidHirtle> ("objective" is what e.g. OWL UC&R document calls "nice to have" features)

<DavidHirtle> (see http://www.w3.org/TR/webont-req/#section-objectives)

<sandro> Axel: this sounds like an open research question

<AxelPolleres> ChrisW: next issue, this requires further discussion.

<AxelPolleres> "a condition in a RIF rule may be a SPARQL query."

<AxelPolleres> Chris W: should be "for example SPARQL"

<Harold> Oracular is not a great term.

<Harold> Black box is better.

1.1.3.b Support oracular models

<AxelPolleres> ChrisW: this is unclear.

<AxelPolleres> Harold: better callout to "blackboxes". Oracle is bad wording.

<AxelPolleres> ChrisW: One could argue that this is a violation of the "no surprises" requirement.

<AxelPolleres> Axel: doesn't this link to semantic annotations of services.

<AxelPolleres> ACTION: csma to explain why this "blackboxes" is not a contrdiction to "no surprises" [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action05]

<sandro> (more than "External Queries")

<AxelPolleres> csma: merge with "external calls"?

<sandro> we're re-dialing, Mike,

<mdean_home> thanks

<DavidHirtle> scribenick: aharth

<sandro> can you hear?

<mdean_home> intermittently

<sandro> now?

<mdean_home> mostly

<aharth_scribe> next topic: markup of semantics

<AxelPolleres> metanote: I will paste what was lost by the lack of connection now!

<AxelPolleres> ======================

<AxelPolleres> AxelPoller: 1.1.2.e.b part one is not feasible, part b should be rephrased.

<AxelPolleres> AxelPoller: ACTION: Dave to rephrase 1.1.2.e.b

<AxelPolleres> AxelPoller: topic: 1.1.2.f RIF should support uncertain and probabilistic information

<AxelPolleres> AxelPoller: ChrisW: needs further discussion.

<AxelPolleres> AxelPoller: topic: 1.1.2.g All requirements that are under the CSF 'Alignment with Semantic Web'

<AxelPolleres> AxelPoller: ChrisW: needs further discussion.

<AxelPolleres> AxelPoller: topic: 1.1.3. Extensibility

<AxelPolleres> AxelPoller: topic: 1.1.3.a Support typed languages

<AxelPolleres> AxelPoller: Paul: datatypes like XMLSchema types, etc.

<AxelPolleres> AxelPoller: Gary: typechecking for functions and predicates.

<AxelPolleres> AxelPoller: Josb: Datatypes or also ObjectTypes, with OWL compatibility we have part of this already.

<AxelPolleres> AxelPoller: ChrisW: this is NOT an anchor into OWL.

<AxelPolleres> ======================

<aharth_scribe> sandro: if you extend the language that might break some things

<aharth_scribe> bonatti: we might have a translation from one dialect to another which is not complete, i.e. doesn't cover all features

<aharth_scribe> csma: if you retrieve a ruleset that you cannot process completely it should not break your application?

<aharth_scribe> chris: anyone who thinks they understand that requirement?

<AxelPolleres> isn't this like "must understand" in SOAP, e.g.?

<sandro> it's closely related, Axel.

<aharth_scribe> harold: title is a repetition of the earlier title, should be able to interchange the semantics

<aharth_scribe> paul: is this talking about partial coverage of the semantics? part of the graceful degredation aspect?

<sandro> Yes -- it will result in the same designs

<aharth_scribe> dave/chris: move this to the next requirement which covers conformance?

<aharth_scribe> chris: rif must be extensible is a requirement?

<aharth_scribe> sandro: that's more a sucess factor

<aharth_scribe> csma: the charter says we must specify "how out of scope features can be expressed by extensions"

<aharth_scribe> ... inability to extend should be addressed by text that explains

<aharth_scribe> csma: are there two different types of extensibility which need to be made explicit?

<aharth_scribe> chris: is the issue whether it's a req or a critical success factor?

<aharth_scribe> ... let's move on

<aharth_scribe> ... conformance model

<aharth_scribe> jos: what is a conformance model? if you have a specified semantics, you know what the language means

<aharth_scribe> csma: first is the granularity level, the other is related to the processing model

<aharth_scribe> ... how do you know that the other side is able to process your rule

<aharth_scribe> sandro: how do you do conformance in the face of extensions?

<sandro> (that's what this addresses)

<aharth_scribe> ... is another way of saying it

<aharth_scribe> chris: any objections to this as requirement?

<aharth_scribe> ... general agreement, no objections

<aharth_scribe> csma: we're done with goal 1

<aharth_scribe> ... next one is low cost of implementation

<aharth_scribe> davidhirtle: in the diagram there is no requirement supporting the low cost of implementation point

<aharth_scribe> sandro: there are, e.g. using XML (for parsing)

<aharth_scribe> csma: fact that it opposes other requirements means we have to find a trade-off

<aharth_scribe> sandro: rif should be implementable using well-understood techniques

<aharth_scribe> csma: rif should not contain features that are not covered by existing languages, implementing reasoners is out of scope for rif

<PaulaP> +1 to csma

<aharth_scribe> gary: what this means to me that you need to get ~~a partial conformance if you comply with some minimal rif subset

<aharth_scribe> ~/s/~~a//

<sandro> Gary: It should be possible get an easy mark of compliance, without supporting lots of stuff.

<aharth_scribe> chris: does that mean there are degrees of compliance?

<aharth_scribe> csma: then, what do you do with the part you don't support?

<aharth_scribe> chris: the current wording is overly vague

<aharth_scribe> dave: one is under extensibility, while the other point is what's in a "rif core"?

<aharth_scribe> chris: rewording: "there are conformance levels, and not all compliant aplications are supposed to support all of rif"

<aharth_scribe> sandro: object to trivial compliance

<aharth_scribe> chris: there needs to be some minimal compliance

<aharth_scribe> csma: postponed the "unnecessary burden" requirement

<aharth_scribe> next one: well-understood implmentation techniques

<sandro> general agreement on No Unnecessary Burden

<aharth_scribe> csma: do we need to be more precise when we talk about rif implementation? reasoners vs. translators

<aharth_scribe> chris: rif should be implementable - no objections

<aharth_scribe> jos: implementable is not low cost of implementation

<sandro> approved: RIF should be implementable using well understood techniques"

<aharth_scribe> chris: next - use of standard support technologies such as XML parsers

<aharth_scribe> chris: XML is not necessarily low cost

<aharth_scribe> csma: XML syntax is a requirement from the charter

<aharth_scribe> chris: XML syntax should be under W3C compatibility

<aharth_scribe> csma: support XML as data is different to XML as syntax for rif

<sandro> Gary: reuse existing reasoners

<aharth_scribe> gary: reuse e.g. XSLT to translate from RIF to other formats

<aharth_scribe> chris: lunch!

lunch

<Harold> Lunch-time discussion between Hassan, DavidR, Sandro, and me:

<Darko> scribe: Darko

Use Cases

csma: 2 new use cases to be added
... is there any modification you want to add to current use cases?
... once we have UCs to cover all needs, we will clean them up and refine them

Axel: Publications of rules to be added as a new UC

<DavidHirtle> http://www.w3.org/2005/rules/wg/wiki/Rules_for_a_Credit_Approval_Service

<DavidHirtle> Gary's use case

<AxelPolleres> http://www.w3.org/2005/rules/wg/wiki/UCR/Candidate_Use_Cases_for_2nd_Draft/PublicationAlternative

csma: comments About Gary's UC?

Sandro: the particularly example fragment of the rulebase is confusing

csma; objections to add this UC to the document?

csma: no objections
... this UC will be in the 2nd WD

<sandro> RESOLVED: To include http://www.w3.org/2005/rules/wg/wiki/Rules_for_a_Credit_Approval_Service in UC WD2 (with possible editorial changes)

UC: Vocabularly Mapping for Data Integration

<sandro> ACTION: DaveR to propose new text for Use Case 8, due 7 July [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action06]

csma: ex publication UC was not clear enough and it was removed

<sandro> http://www.w3.org/2005/rules/wg/wiki/UCR/Candidate_Use_Cases_for_2nd_Draft/PublicationAlternative

<sandro> Hey, Alex.

csma: objections to Axel's UC?
... no objections. RESOLVED it will be added

<AlexKozlenkov> Well, I a permanent British resident but have been lazy applying for a British passport

<AlexKozlenkov> I was in Croatia a few years ago and didn;t require a visa--now they've changed the rules

<AlexKozlenkov> Dixi

David: 3 comments on the current publication (1.about ontolgies, 2.by Sven, 3.about XML data)

<AlexKozlenkov> Zakim mute me

<scribe> ACTION: David to add pointers from the UC documet to requiremts by the end of this month [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action07]

<Harold> Alex, do you want to bring your use case on the phone?

Axel: 1 week since last comment is needed

<AlexKozlenkov> I could if the line was better, so far I'm struggling hearing anything

<Harold> Perhaps type in a distilled version here.

<sandro> What's it sound like, Alex?

<scribe> ACTION: Gary: take commets into account and send new version of the UC in 1 week [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action08]

<DavidHirtle> we may be able to hear you better than you can hear us, Alex

<AlexKozlenkov> Sandro, it's breaking like the sound is tearing

<DavidHirtle> (we're not always so good at getting the mic passed around)

<Harold> great

<scribe> ACTION: Axel to collect comments by this Friday and send new version of the UC and the next Friday [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action09]

<Harold> we ccan hear you well.

<Harold> Please speak up a bit.

<Harold> Louder.

<Harold> Try once more.

Alex will send his UC via email

<scribe> ACTION: Alex to send his UC via email [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action10]

<Harold> Alex, can you elaborate on the sketch you sent?

<sandro> Maybe Alex should do it on the Wiki, like the other use cases....?

csma: more comments on the UC section?

<AlexKozlenkov> A short ouline posted

<ChrisW> is it audible now?

<ChrisW> (the phone)

RIF-RAF

<ChrisW> peter, are you there?

<ChrisW> alex, can you hear better now?

<AlexKozlenkov> Nope

<AlexKozlenkov> Now there is total silence

<sandro> pfps, Alex -- we have disconnected the Phone->Room connection for now, since it was just causing noise and didn't seem to be helping.

<AlexKozlenkov> I see

<AlexKozlenkov> I'm hanging up then?

<ChrisW> can you hear paul now?

<AlexKozlenkov> It's actually better now!

<sandro> No, Alex, you should be able to hear

Paul is giving presentation on OMG Production Rules

<ChrisW> (there was a brief break)

<sandro> AlexKozlenkov, pfps -- the disconnection is only on sounds from Phone to the room -- this should make Room -to- Phone work better.

<ChrisW> if you want to speak, then let us know on IRC

<AxelPolleres> If somebody on the phone wants to say something, klet us know, we have to turn on the microphone in this case.

<AlexKozlenkov> Are you aware of a company called Kabira who has a similar MDA driven process with a custom workflow input?

<ChrisW> (not sure that will work any better than before, though)

<sandro> AlexKozlenkov, do you want me to speak that?

<LeoraMorgenstern> I can't hear a thing; is anything happening?

<AlexKozlenkov> Yes that would be good!#

<AxelPolleres> Alex, can you paste a URI of this on irc

<AxelPolleres> ?

<ChrisW> Leora, you cannot hear PaulV?

<AlexKozlenkov> http://www.kabira.com/

<LeoraMorgenstern> Never mind; now I can hear. Not terribly well,

<sandro> LeoraMorgenstern, Can you hear Paul talking now -- talking about standards at OMG, UML, etc?

<LeoraMorgenstern> Yes, I can hear --- fuzzy, but I can hear.

<sandro> That's about as good as it's going to get today, I'm afriad. We'll try to have better microphones tomorrow.

<LeoraMorgenstern> I'm glad to hear something --- thank you!

<sandro> Paul apologized that the slides he's using are not available yet, but he'll mail them out shortly.

<AlexKozlenkov> Question to Paul: can actions be grouped together as a transaction?

<AlexKozlenkov> Thanks

<AlexKozlenkov> no sound now

<LeoraMorgenstern> same here

<ChrisW> the phone hung up

<ChrisW> hold on

<LeoraMorgenstern> Okay, thanks

<AlexKozlenkov> yes, you are back

<AlexKozlenkov> yes

<LeoraMorgenstern> i can hear

<AlexKozlenkov> Paul, any link for the action language? Are communication actions supported?

<AlexKozlenkov> yes please

<GiorgosStoilos> ACTION: csma to check whether OMG is okay with their member-only documents being sent to member-rif-wg (W3C member only list) [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action11]

RIFRAF

<sandro> http://www.w3.org/2005/rules/wg/wiki/Rulesystem_Arrangement_Framework

<GiorgosStoilos> chrisW: RIFRAF is to characterize different rule systems

<GiorgosStoilos> ...different types of semantics in rule systems

<GiorgosStoilos> Harold: it is a classification system

<GiorgosStoilos> Gary: it cannot be used for reactive rules at this point

<GiorgosStoilos> chrisW: we need to extend some discriminators of RIFRAF to cover other staff we are discussing about

<sandro> (confusion about rifraf 1.1.)

<AlexKozlenkov> no sound

<sandro> sorry -- conversation is moving too fast to move the mic

<AlexKozlenkov> Okay

<GiorgosStoilos> chrisW: rifraf 1.1 seems to be about scope

<sandro> Harold: Existential variables, anonymous variables

<sandro> Hassan: the head of a rule in LP is sometimes constrained to have all distinct variables

<GiorgosStoilos> ACTION: Harold to add some examples for rifraf 1.1 [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action12]

<sandro> Harold: forward-chaining woulod generate non-ground-facts, without range restriction

<GiorgosStoilos> Gary: rifraf 1.2 discriminator for production rules also

<sandro> Axel: typed variables should go here

<GiorgosStoilos> chrisW: 1.3 is a bit ambiguous

<GiorgosStoilos> harold: is a classical definition from logic programming

<GiorgosStoilos> Dave: why is rifraf 3 an interesting discriminator for RIF?

<GiorgosStoilos> harold: it is interesting to look at the reduction between 2 languages

<GiorgosStoilos> hasan: this is not what we call conservative extension

<GiorgosStoilos> sandro: trnaslating to and back would u get the intial rules, or would L-T have been done?

<GiorgosStoilos> axel: this is a syntactic discriminator; whether u allow complex formulas or not

<AlexKozlenkov> I'm kicked out of RIF Wiki due to surge protection. Given we're shown as one IP, it is possible. Anything can be done at all about it?

<AlexKozlenkov> I'm going to be back for the requirements session at 4

<pfps> no connection on IRC

<LeoraMorgenstern> quit

<GaryHallmark> scribe: gary hallmark

<GaryHallmark> scribenick: GaryHallmark

Requirements

csma: continue sorting based on degree of agreement

<sandro> ... and clarifying wording

csma: widescale adoption/low cost of implementation/low transfer cost

sandro: split it up
... emphasize real time performance

daveR: why real-time goal?

paulV: means low deployment time cost
... low computation cost for consumer

<sandro> "Low Cost of Implementation" ==> cheap serialization

<sandro> small footprint? simple?

paulV: low complexity

<sandro> Latency is a different issue

piero: expressive RIF will yield shorter msgs

<AlexKozlenkov> Could anyone post the link to the very latest list of reqs? Thank you

<DavidHirtle> http://www.w3.org/2005/rules/wg/wiki/UCR/Critical_Factors_Analysis

piero: but expressive RIF may be more expensive to implement

<DavidHirtle> we're on 1.1.2.3

<AlexKozlenkov> Thanks David

csma: need further discussion for this requirement

<bonatti> ...and if RIF is expressive enough, one can encode his/her rule base in a compact way

<DavidHirtle> Alex, as we discuss them we are modifying some, but these modifications aren't viewable online (yet) unfortunately

<AlexKozlenkov> I see

<EvanWallace> numbering doesn't seem to match

<DavidHirtle> 1.2.3, within section 1

csma: how to measure this requirment?

paulV: 1-10 seconds

<DavidHirtle> (I know it's confusing)

csma: moving right along to new goal: consistency with W3C specs
... RIF should support RDF

<sandro> maybe: sub-second latency on transfer of practical 100-rule ruleset --- something like that.

<EvanWallace> got it

csma: RIF should accept RDF triples as data

paula: means rules work with RDF data

paulV: is this obligatory or just feature?

<AlexKozlenkov> Does it mean that RDF can be only in the body of the rules?

csma: what is relationship with SPARQL?

<DaveReynolds> (b) implicitly talks about RDF in head, we are currently talking about (a) which, yes, is about the body

sandro: RDF more integrated than blackbox SPARQL

<AlexKozlenkov> It's patchy

<AlexKozlenkov> I can hear some speakers well

sandro: need RDF in reactive rules not just Horn

<EvanWallace> I can't hear any speakers well

sandro: all RIF dialects should accept RDF triples
... as data

<AlexKozlenkov> Gary, what about SQL data?

<EvanWallace> Can someone scribe PaulV's question re: rdf data

paulV: is RDF a requirement (mandatory?) of RIF or all rule languages using RIF?

<pfps> If the RIF can't handle Semantic Web data, then what is the RIF WG doing in the SW activity?

sandro: must all RIF dialects support integers?
... yes
... and so for RDF triples

csma: need more discussion

sandro: ambiguous: RDF as serialization format vs. RDF as data model

<sandro> RDF Data Model vs RDF/XML Serialization

sandro: RDF brings along XML Schema datatypes

csma: rephrase to: RIF should support RDF data model?

daveR: if its in RIF core, its in all extensions, too

paulV: this is a strong constraint

chrisW: can't constrain all rule languages

sandro: need to define conformance

davidH: requirement is on RIF, not on rule languages

<sandro> sandro: If you want conformance to RIF, then you need to support ....

csma: again, needs more discussion
... next: RIF should support RDF deduction rules
... no objection

Axel: what does "cover" mean?

Sandro: e.g. RDF deductions available as additional RDF data

<sandro> So this is a shortcut for RIF Must Cover N3 / Jena Rules

Axel: ok

csma: SPARQL queries covered this morning, Dave has action
... next: Support OWL - are issues here the same as with RDF data?

kifer: is every OWL feature required?

josb: may depend on how it is integrated - e.g. like SWRL or more loosely

daveR: can't presuppose blackbox (loose) integration

<sandro> If blackbox approach to OWL integration, then this is the same as call-out. But not all support that.

josb: pfps may want to comment

sandro: need to resolve phasing to make more progress here, for ALL requirements

<sandro> pfps, you're not actually listening, are you?

action on josb: clarify this requirment

<sandro> ACTION: josb to disambiguate http://www.w3.org/2005/rules/wg/wiki/The_RIF_Core_must_be_able_to_accept_OWL_KBs_as_data [recorded in http://www.w3.org/2006/06/08-rif-minutes.html#action13]

csma: next: support XML

kifer: need more precise defn

paulV: often used by PR

sandro: map xml to prolog term

<sandro> mkifer: there's anb approach where you use XML documents as templates

kifer: is this similar to xml extensions to SQL?

csma: can owl, rdf, and xml data be generalized to "data source"?

sandro: seems straightforward

<sandro> sandro: I think it's important to approve this requirement, as is

chrisW: RIF should handle interchange of XML data without translation

<sandro> DaveR: yes, but also for RDF

chrisW: ditto for RDF and OWL

<AlexKozlenkov> I'm wondering if direct access to SQL should be allowed. That would allow us to tap into the world of industrial databases

<sandro> Sandro: There are two kinds of compatibility with RDF -- at the low model level, I want that in ALL dialects; at the detailed level it can be only in some dialects

<sandro> DaveR: "You can do useful pattern matching on XML documents"

csma: set of requirements around data sources and external calls (sparql, xslt, etc)
... should deal with them in a uniform way

<bonatti> sribe: piero (bonatti)

<josb> scribenick: bonatti

permit XML info types to be expressed using XML schema

csma: equivalent to supporting built-in XML elements?

<DavidHirtle> see: http://www.w3.org/TR/xmlschema-2/#built-in-datatypes

csma: (equivalent to David's point)

<DavidHirtle> (to avoid confusion)

<sandro> Charter: In Phase 1, the format must support literals and common functions and operators for at least: text strings (xsd:string), 32-bit signed integers (xsd:int), unlimited-size decimal numbers (xsd:decimal), Boolean values xsd:boolean), and list structures.

<sandro> 2.3.

<sandro> -- http://www.w3.org/2005/rules/wg/charter

Dave: need clarification

hassan: what extend of XML schema is to be supported?

sandro: streese is more than elemntary datatypes - he mentions lists

dave: he mentions restrictions to datatypes

csma: this needs to be clarified

<sandro> Clarify relationship to XS unions and restrcitions on types

<sandro> DaveR: RIF must be clear about which XS features are required for Conformance

csma next: RIF should cover LP + negation as failure and strong negation

<sandro> "Strong Negation" is more related to 3-values, or maybe intuitionistic/constructive. No Excluded Middle.

csma: not clear what strong negation means

<sandro> summary: Strong Negation is like Classical Negation but without Law Of Excluded Model -- part of stable model semantics.

<sandro> Piero: There is no interplay between positive and strongly-negated atoms. Strongly-negated atoms are like atoms re-written.

bonatti: strong megation can be "implemented" by replacong strongly negated atoms with new atoms uniformly
... puts no requirements on negation as failure (such as stratification)

<josb> strong negation is part of the answer set semantics, which in turn is based on the stable model semantics; strong negation is an extension of the stable model semantics

<sandro> DLV supports both

<sandro> => "strong negation" as in DLV

csma: let's use DLV as reference to specify what we mean

harlod: Wagner (REWERSE) has proposed/supported strong negation

sandro: isn't this good for phase 2?

<sandro> Handle this under Phase-2-RIFRAF.

csma: maybe such things should be discussed as a whole

<josb> THE reference on strong negation in logic programs, implemented in, e.g. DLV: http://citeseer.ist.psu.edu/gelfond91classical.html

module constructs for scoped positive and negationas failure queries

harold modules similar to contexts etc

scribe: efficiency is important

csma: can we propose concrete languages needing this?
... poroperty of a language, not RIF

Josb: many languages (eg flora) have modules and have to be exchanged

harold: modules should be a requirement

<AlexKozlenkov> I have a question, should each individual rule have unique id? Also, if module id can be dynamically assigned, one could add/remove rulesets in one step.

sandro: working memory, a DBMS are example of scopes

<AlexKozlenkov> What I am saying is that rules may accessed both individually and as groups

csma: needs discussion, strongly related, actually belongs to, RIFRAF

<sandro> PROPOSED: add a requirement that all features

<sandro> PROPOSED: add a requirement that all features in RIFRAF are requirements

davidh: add a requirement saying that all prioritized features described in RIFRAF are to be covered by RIF

<DavidHirtle> (something like that)

<sandro> DaveR: We'll use RIFRAF to identify the features we cover

PROPOSED: RIFRAF will identify the set of languages to be covered by RIF

<sandro> DaveR: We'll use RIFRAF to identify the set of language features RIF may cover

<sandro> PROPOSED: Every feature in RIFRAF will be discussed in the future as a possible Requirement.

<sandro> Harold: No -- they are orthogonal

<GaryHallmark> RIFRAF must be "larger" than the set of requirements (currently it is not, e.g. reactive rules)

<sandro> PROPOSED: We will use RIFRAF to identify classes of language to be covered by RIF

<sandro> PROPOSED: We will use RIFRAF to identify classes of languages to be covered by RIF

<sandro> RESOLVED: We will use RIFRAF to identify classes of languages to be covered by RIF

<AlexKozlenkov> RIFRAF surely has more bearing on derivation rules

<AlexKozlenkov> Does ot mean that RIFRIF will be extended to cover, say, reaction rules?

<sandro> AlexKozlenkov, what you're seeing is that RIFRAF right now only covers phase one -- Horn rules.

next topic: tagging intended semantics: already discussed

<DaveReynolds> Alex, yes I would say it should

<AlexKozlenkov> Can we explicitely mention that it will be extended, so that it is written down

higher order and frame based syntax: 2 requirements, moved to RIFRAF

<sandro> It should be in the minutes of the RIFRAF session earlier today, I think, Alex.

<AlexKozlenkov> OK, thanks, Sandro

harold: for each dimension there can be multiple choices - e.g. extent of support to function calls (prolog example)
... not every combination of features in RIFRAF shall be supported

consistency w. major market technologies

chrisW 1-3 look like requirements

gary: 1 and 2 similar to the data sources issue

csma: nobody really understands "UML Instances": it should be postponed

<sandro> Category -- data access by rules

chrisW: should we describe these languages as classes of RIFRAF features?

<sandro> "Data Sources"

<EvanWallace> Sound dropping out a lot

<AlexKozlenkov> I guess the mic is not being passed around really

<sandro> RIght. It's incredibly hard/expensive to pass the mic around, so we sometimes give up on it.

dave: let's move the SBVR point to RIFRAF and discuss "UML instances " and ORM fact model populations"

<sandro> Tomorrow, we're supposed to have more mics

<AlexKozlenkov> Perfectly understandable, I was just commenting on the sound dropping

<EvanWallace> Fine. Then scribe better.

<sandro> Very funny, EvanWallace. :-)

<sandro> (bonatti is scribing this session.)

gary: some languages can import business obj model from UML

<sandro> (it's simliarly hard to scribe everything said in a fast-moving discussion.)

csma: this has to do with sharing obj models - this is orthogonal

<AlexKozlenkov> Eclipse Ecore/EMF is one way to store UML instances, one can run OCL queries on it, one could also imagine a RIF integration

paulv: representing OCL as rules is an interesting topic, too

meta-data for currency of rules

<AlexKozlenkov> OCL querying on EMF instances is actually quite cute

UNKNOWN_SPEAKER: refers to rule validity (in time)

<AlexKozlenkov> Integrating EMF instances with RIF has value

csma: it has to do with rule management, not interchange

<AlexKozlenkov> I see

paulv: it is redundant - it could be done in rule languages that support time

hassan: no, it has rather to do with versioning

chrisW: the wiki page mentions "retrospective analysis"

paulv: such a "what-if" kind of reasoning is beyond the scope of RIF

dave: time validity could be part of the metadata (rule-tagging) effort

csma: discuss later with metadata

<sandro> Charter: RIF "must include a way to express facts as well as rules, and also metadata (annotations) about documents, facts, and rules. "

<Harold> Piero and All, RE: "e.g. extent of support to function calls (prolog example)" I meant "e.g. to support vs. not to support user/equality-defined functions (LIFE vs. Prolog)". This is an example where pointing to a RIFRAF dimension is not enough to express a design constraint: You have to say which value you pick in that dimension. For details see Hassan's email on logic with equality.

csma: having time validity means that a compliant application should ignore them if outside validity period

<AlexKozlenkov> There is a whole range of issues related to rules management. E.g., is RIF concerned with the rights management?

chrisW: not like "author" meta-tags: validity tags affect execution/reasoning

dave/csma: there is a requirement that RIF covers metadata: should we discuss it or just provide a mechanism to add metadata?

<AlexKozlenkov> One could say: limit inference to specific rules source/origin

<AlexKozlenkov> Extensible metadata should be a requirement. We cannot predict all the types of metadata people would want to associate with rules

gary: the question is about metadata in general

passing descriptive text through RIF

UNKNOWN_SPEAKER: i.e. something like comment tags

chrisW: if this just means "comments" then we all agree

agreement.

metadata indicating exedcutability of rules

<AlexKozlenkov> Aren't comments part of metadata?

<LeoraMorgenstern> aaaa is LeoraMorgenstern

UNKNOWN_SPEAKER: needs further discussion

RIF scope - exchange of RDFS/OWL fact models

davidh: only some of the issues here are requirements

csma: it duplicates previous discussion on data sources

gary: during last f2f facts were distinct from data

harold: data are not given any model-theoretic meaning

csma: it's inthe data source discussion

4 modal operators

csma; goes to RIFRAF

paula: Allen made a proposal not in the list of issues on design constraints: should it be discussed?
... it can be found in the e-mail archive

csma: it won't be in the draft to be produced on friday, so its discussion is postponed

<AlexKozlenkov> I find it impossible to follow on the phone, I'm hanging up--will be following on the IRC

<Darko> -Darko

csma: meet you all tomorrow at 8...

<sandro> Telephone: goodnight!

<EvanWallace> goodnight

- DRAFT -

SV_MEETING_TITLE

8 Jun 2006

Attendees

Contents

Goals and CSF

Break

Requirements

1.1.1.b Interchange of rule sets will often involve different semantics ...

1.1.1.c Markup of semantics

1.1.2 Coverage

1.1.2a The RIF should support deduction rules

1.1.2.e Combined rulesets

1.1.3.b Support oracular models

lunch

Use Cases

RIF-RAF

RIFRAF

Requirements

permit XML info types to be expressed using XML schema

module constructs for scoped positive and negationas failure queries

higher order and frame based syntax: 2 requirements, moved to RIFRAF

consistency w. major market technologies

meta-data for currency of rules

passing descriptive text through RIF

metadata indicating exedcutability of rules

RIF scope - exchange of RDFS/OWL fact models

4 modal operators

Summary of Action Items

Scribe.perl diagnostic output