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These minutes have been approved by the Working Group and are now protected from editing. (See IRC log of approval discussion.)

See also: IRC log, Agenda


Agenda amendments: amendment on RIF OWL compatibility issue

Michael Smith: IanH, the amendment was added by pfps

(see below under #Additional other business)

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Accept previous minutes?

Alan Ruttenberg: +1
Zhe Wu: +1
Doug Lenat: +1 on minutes

Previous minutes accepted

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Zhe Wu: cash only ?

Cheques are also accepted on-site

Action items

Action 113 completed

Alan Ruttenberg: Need to continue my actions 101, 114 - will adjust dates

Action 105 completed

Action 72 due tomorrow

Action 76 delayed, to be done soon (before F2F2)

Action 86 delayed

Action 90 delayed, discussion scheduled for F2F2

Action 100 remains open (James Hendler not on call)

Action 101 delayed, to be done for F2F2

Action 102 remains open (James Hendler not on call)

Action 104 completed

Action 109 completed

Action 93 completed

Action 114 completed


Issue 86

Issue 86

Michael Smith: yes, this proposal was from alan
Peter Patel-Schneider: I just sent out a slight modification to the proposal (which should not change anyone's vote).

Alan Ruttenberg: new updated proposal is indeed editorial, minor correction only

Michael Smith: inverse properties could also be handled in RDF mappnig by swapping object and subject and adding an annotation for enabling round-tripping

Alan Ruttenberg: annotations should not have any logical meaning

Ian Horrocks: the annotation was just for round-tripping, no logical impact

Alan Ruttenberg: I doubt that exchanging subject and object always works

Ian Horrocks: yes, it is obvious only for facts, but not for restrictions

Michael Smith: I think facts are the only case where this applies, there is no problem with inverses in restrictions

Jeremy Carroll: I agree with msmith, it is only a problem in facts

Peter Patel-Schneider: Should we have a vote to go forward for now, but get a revised proposal?
Michael Smith: we can separate nested inverses from this issue

Alan Ruttenberg: Jeremy referred to the problem of multiple (nested) inverses; I also think that this should be disallowed

Jeremy Carroll: i much prefer mike's proposal
Jeremy Carroll: yes i am sure

Ian Horrocks: there seem to be two competing proposals now

Alan Ruttenberg: if it is just about facts, then Michael Smith's proposal might work as well

Alan Ruttenberg: indeed

Ian Horrocks: does anybody doubt that Michael Smith's proposal works?

Alan Ruttenberg: have to think about anonymous individuals and Mike's proposal

Jeremy Carroll: my problem with it is that the proposal requires annotating the triple for round-tripping

Uli Sattler: Jeremy, please repeat
Alan Ruttenberg: push to email, I think

Ian Horrocks: Who thinks that Alan Ruttenberg's proposal is the way to go

PROPOSED: Alan Ruttenberg's proposal

Alan Ruttenberg: 0 (want to think about Mike's first)
Uli Sattler: 0
Doug Lenat: 0
Achille Fokoue: 0
Jeremy Carroll: -0.1
Peter Patel-Schneider: +1 for Alan
Zhe Wu: 0
Diego Calvanese: 0
Markus Krötzsch: 0
Sandro Hawke: 0
Jie Bao: 0
Ratnesh Sahay: 0
Ivan Herman: 0
Michael Smith: +1 to using annotations, but iff round-tripping is a requirement

PROPOSED: who thinks that Michael Smith's proposal is the way to go?

Peter Patel-Schneider: -1 for mike
Sandro Hawke: 0
Jeremy Carroll: +0.4
Evan Wallace: 0
Alan Ruttenberg: 0 (want to think about it first)
Zhe Wu: +0
Doug Lenat: -0.5
Achille Fokoue: 0
Uli Sattler: 0 (the same, need to think)
Achille Fokoue: -0
Bernardo Cuenca Grau: 0

Michael Smith: could we have a strawpoll on whether we wish to support ObjectProperty assertions where properties are inverses at all

Michael Smith: it might be that we do not really need that

Michael Smith: I suggested to disallow this in an email

Alan Ruttenberg: not facts
Alan Ruttenberg: only restrictions
Alan Ruttenberg: objectAllValuesFrom := 'ObjectAllValuesFrom' '(' objectPropertyExpression description ')'
Alan Ruttenberg: inverseObjectProperty := 'InverseObjectProperty' '(' objectPropertyExpression ')'
Alan Ruttenberg: objectPropertyExpression := objectPropertyURI | inverseObjectProperty

Boris Motik: support for inverse properties without explicitly naming them was requested from the DIG working group, and is used in many reasoners

Ivan Herman: What is the DIG working group?
Bernardo Cuenca Grau: Ivan, Description Logics Implementors group
Bernardo Cuenca Grau: A group of people that have implemented DL reasoners. It includes the people who have developed the major DL reasoners.
Bernardo Cuenca Grau: Peter is a member; I think so is Ian.

Ian Horrocks: further discussion needed, to be taken to email

Michael Smith: more email sounds good

Jeremy Carroll: can we have a strawpoll on disallowing inverses as proposed by Michael Smith?

Alan Ruttenberg: disallowing means no InverseObjectProperties inside Fact constructs

PROPOSED: disallow anonymous inverse properties in facts

Boris Motik: -1
Jeremy Carroll: +1
Uli Sattler: -1
Markus Krötzsch: -1
Peter Patel-Schneider: -1 AIPs have their place in the world
Alan Ruttenberg: 0
Zhe Wu: +0.1
Jie Bao: 0
Achille Fokoue: +1
Bernardo Cuenca Grau: -1
Evan Wallace: -1
Diego Calvanese: 0
Doug Lenat: 0 (need to think about it)
Rinke Hoekstra: 0
Ivan Herman: 0
Diego Calvanese: 0
Michael Smith: +1 to disallowing anonym in obas
Sandro Hawke: 0

Issue 12

Issue 12

Alan Ruttenberg: I suggested a modification for improving efficiency (see

Peter Patel-Schneider: Alan's proposal might be problematic, since it adds totally new different individuals

Alan Ruttenberg: But it is only an existential (a bnode)

Peter Patel-Schneider: Yes, but it still might increase the size of the domain.

Peter Patel-Schneider: this creates a burdon on round-tripping

Peter Patel-Schneider: but the creation of new individuals as such is the main problem

Alan Ruttenberg: for equivalent class and equivalent properties it should not be such a problem

Ian Horrocks: not sure without having a closer look

Ian Horrocks: it seems we cannot resolve the issue with that solution without further investigation

Alan Ruttenberg: my proposal for possible optimisation might be a separate issue

Jeremy Carroll: The issue also touches other issues related to reification, and I would currently abstain on this issue until the relations are clearer

PROPOSED: should this issue by closed according to pfps's proposal

Alan Ruttenberg: +1
Uli Sattler: 1
Peter Patel-Schneider: +1 (surprise)
Jeremy Carroll: +0 concur
Doug Lenat: If asked I would respond +1
Zhe Wu: 1
Jie Bao: +1
Evan Wallace: +1
Boris Motik: +1
Markus Krötzsch: +1
Ivan Herman: 0
Boris Motik: +1
Michael Smith: +1
Boris Motik: +1
Rinke Hoekstra: +1
Ratnesh Sahay: 0

PROPOSED: close Issue 12 as in pfps's email provided that new information does not come in and noting that this does not close the general reification issue

Alan Ruttenberg: considering as possible new information
Peter Patel-Schneider: +1
Doug Lenat: +1 (peter's typing might be that new info of course)
Alan Ruttenberg: +1
Michael Smith: +1
Ian Horrocks: +1
Markus Krötzsch: +1
Uli Sattler: +1
Rinke Hoekstra: +1
Achille Fokoue: +1
Jeremy Carroll: +0 concur
Zhe Wu: +1
Boris Motik: +1
Evan Wallace: +1
Bernardo Cuenca Grau: +1
Ratnesh Sahay: 0
Sandro Hawke: 0
Diego Calvanese: 0
Ivan Herman: 0

RESOLVED: close Issue 12 as in pfps's email provided that new information does not come in and noting that this does not close the general reification issue

Sandro Hawke:

Ian Horrocks: Time for issues is up, proceed with reviews of candidate working drafts first

ACTION: bmotik2 to Update the RDF mapping with the accepted resolution of Issue 12 as per Peter's suggestion

trackbot-ng: Created Action 115 - Update the RDF mapping with the accepted resolution of Issue 12 as per Peter's suggestion [on Boris Motik - due 2008-04-02].

Reviews of candidate FPWDs

Fragments document

Achille Fokoue: I corrected minor problems, and raised issues where needed

Michael Smith: mostly editorial comments, not put into wiki page yet

Alan Ruttenberg: uncontroversial editorial changes can be made directly in the document

Michael Smith: OK, I will shortly incorporate my comments then

Sandro Hawke: we might want to change the document title (wiki page name currently is Fragments Proposal)

Sandro Hawke:
Alan Ruttenberg: "Fragments of OWL"

Alan Ruttenberg: "Fragments of OWL" seems to be a good name

Sandro Hawke: "Language Fragments"
Peter Patel-Schneider: owl pieces / owl bones

Ian Horrocks: I would just say "OWL Fragments"

Ian Horrocks: Actually just "Fragments" would be good

Alan Ruttenberg: "Fragments" ok by me
Zhe Wu: "OWL Fragments" sounds good
Bernardo Cuenca Grau: To be consistent with the other documents we should simply say "Fragments"
Peter Patel-Schneider: syntax is Syntax, so fragments should be ... Fragments
Rinke Hoekstra: "Fragments"

Jeremy Carroll: the abstract of the fragments doc is insufficient

Jeremy Carroll: also, the term "fragment" may have a negative connotation

Peter Patel-Schneider: -1
Uli Sattler: "species"
Bernardo Cuenca Grau: no species

Alan Ruttenberg: "profiles"?

Boris Motik: "Fragment" is a standard term from logic.
Bernardo Cuenca Grau: Yes
Peter Patel-Schneider: To change the name requires moving the page, I think
Jeremy Carroll: fragment may be a term from logic, but ...

Ian Horrocks: this discussion should be continued offline

Zakim: jjc, you wanted to mention abstract
Peter Patel-Schneider: An abstract is, by definition, one paragraph. (Yes this is often violated.)

Achille Fokoue: I would like an additional review of the changes I made recently

Boris Motik: I can review Achille's changes.
Michael Smith: achille, I will review again with your edits in mind

Diego Calvanese: regarding the DL Lite fragment, I think major changes are still required in the document

Diego Calvanese: for example function properties should be there

Bernardo Cuenca Grau: Diego, remember that we have role hierarchies
Bernardo Cuenca Grau: Wouldn't functionality be problematic?

Diego Calvanese: several other additions could be made

Peter Patel-Schneider: we can note in the current version that the presented DL Lite fragment is a conservative fragment that is likely to be extended later on

Alan Ruttenberg: +1 to pfps
Doug Lenat: good point
Diego Calvanese: +1 to pfps
Boris Motik: I can do it
Diego Calvanese: ok

ACTION: bmotik to add a note to the fragments document regarding possible later extension of DL Lite

trackbot-ng: Created Action 116 - Add a note to the fragments document regarding possible later extension of DL Lite [on Boris Motik - due 2008-04-02].
Michael Smith: bmotik, suggest merging note about Issue 80 into it
Boris Motik: Msmith, good point about Issue 80; will do.

XML Serialisation

Achille Fokoue: my comments were already addressed by pfps

Achille Fokoue: the document is in a good shape overall

Sandro Hawke: I noticed inconsistent uses of namespaces

Sandro Hawke: maybe we should add a note that the namespaces might be changed later

Alan Ruttenberg: q+ to say s/owl11xml:/ox:/

Ian Horrocks: it would be good to have a sensible solution eaerly on, so as to prevent people using placeholders that are changed later

Peter Patel-Schneider: ox is a namespace name not a namespace

Alan Ruttenberg: minor comment to change the namespace prefix in the schema to the one used in the text

Alan Ruttenberg: there are still inconsitent namespace prefixes in the document

Alan Ruttenberg: owl11xml:EntityAnnotation
Alan Ruttenberg: ox:EntityAnnotation

Alan Ruttenberg: my second comment is about "abstract" and "concrete" classes; the use of those terms is not fully clear yet

Alan Ruttenberg: Example quote from document: "Each abstract class (i.e., a class that is not intended to be instantiated, but is used to define a class hierarchy) is mapped to a global element group."
Michael Smith: on namespaces, I've verified that we've been using , because this what is what the OWLAPI uses
Boris Motik: Yes.

Ian Horrocks: Who has implemented OWL 1.1 software? Which namespaces would users prefer?

Boris Motik: I do not think users would care much; I have not received any user comments on that

Alan Ruttenberg: We still should not change the namespace if there are already OWL 1.1 ontologies

Boris Motik: I think there are not so many OWL 1.1 ontologies that would be affected there

Michael Smith: I posted the namespaces used in the OWL API into IRC

Michael Smith: I also think that there is no problem in changing the namespace now

Sandro Hawke: I would prefer a non-dated namespace now

Rinke Hoekstra: +1 to undated namespace

Ian Horrocks: yes, I also would like to not have dates in the namespace

Sandro Hawke: yes, the dates were only used to generate unique names, the are not really needed

Sandro Hawke:
Peter Patel-Schneider: OK by me

PROPOSED: use as a namespace

Alan Ruttenberg: +1
Ian Horrocks: +1
Zhe Wu: looks good
Doug Lenat: +1
Bernardo Cuenca Grau: +1
Uli Sattler: +1
Jie Bao: +1
Ivan Herman: +1
Rinke Hoekstra: looks ok, what does the rdf namespace look like?
Achille Fokoue: +1
Diego Calvanese: 0
Markus Krötzsch: +1
Zhe Wu: Is the name "OWL 1.1" fixed then?

PROPOSED: use as the XML namespace name for OWL 1.1 XML serialization

Peter Patel-Schneider: +1
Markus Krötzsch: +1
Ian Horrocks: +1
Doug Lenat: +1 again
Rinke Hoekstra: +1

RESOLVED: use as the XML namespace name for OWL 1.1 XML serialization

Sandro Hawke: A related question is where to publish the schema, but I need to do some more research on this

Alan Ruttenberg:

Zhe Wu: Does this namespace decision imply that the new standard is called OWL 1.1?

Sandro Hawke: Yes, good point ... maybe not "owl11". just "owl"?
Alan Ruttenberg: no [Scribe assist by Ivan Herman]

Ian Horrocks: Should we rather change the namespace to drop the 11?

Peter Patel-Schneider: I prefer .../owl-xml

Jeremy Carroll: We can still change our minds on the namespace later on, since this is just a working draft

Ian Horrocks: Indeed, we can go with the current resolution for the early working draft now


Jie Bao: There is still some work to do. The main question is who will read the Primer.

Jie Bao: I think the document needs to be restructured to become accessible for users of different levels of expertise.

Jie Bao: Advanced topics like Open World Assumption should go to later sections.

Ian Horrocks: Jie, could you and Deborah cooperate with the authors to fix the perceived problems with the Primer until F2F2?

Jie Bao: I think Section 3 and 4 are mostly our problem, but fixing that might not require much time

Alan Ruttenberg: I object that OWA is considered an advanced topic. It is in fact a major point in using OWL

Alan Ruttenberg: I therefore would object to moivng that to the appendix

Uli Sattler: +1 to alanr
Rinke Hoekstra: +1 too
Boris Motik: +1

Doug Lenat: The Primer is far from being ready to be published.

Doug Lenat: whole sections are mostly blank

Doug Lenat: e.g., the advanced features section is not containing advanced features

Doug Lenat: more people from this group should review the Primer, since it is important for the perception of OWL

Doug Lenat: the current content of the Primier is good, but more is needed

Jie Bao: I agree with DougL

Jie Bao: I think that an incremental presentation would be better

Peter Patel-Schneider: we have only two days left to make changes, which seems to preclude any substantial changes before F2F2

Alan Ruttenberg: question is: Should we wait on publishing this?

Peter Patel-Schneider: the missing sections are "Using OWL" and "Using OWL Tools"

Peter Patel-Schneider: not sure whether "Using OWL" is needed

Peter Patel-Schneider: I do not agree, though, that the Primer is not publishable as is

Jie Bao: I may help, but will be minor as Peter and Bijan are the authors
Peter Patel-Schneider: Monday is a travel day!

Alan Ruttenberg: there is a UFDTF meeting this monday where we might discuss this issue

Alan Ruttenberg: would it be harmful to not publish now but in two weeks?

Doug Lenat: It's not "harmful", we can make it very clear that it is a first draft.

Ian Horrocks: we can consider that at the F2F

Sandro Hawke: Publish early, publish often!

Sandro Hawke: we can publish an incomplete document as a working draft

Jeremy Carroll: It would be useful to add a one-sentence summary of the review comments, to indicate open points that are still worked on

Jeremy Carroll: in general we can have comment inline to indicate work in progress

Doug Lenat: that sounds like a workable idea. peter should probably summarize the reviews, not point at them

Peter Patel-Schneider: It will be hard to point to the distributed reviews from the Primer

Sandro Hawke: we should not point to the reviews, but reach a consensus on what needs to be done, and state that in the document

Doug Lenat: Let me reiterate that what is there is quite good.
Uli Sattler: +1 to Doug
Peter Patel-Schneider: The reviewers could come up with a suitable statement for being included in the Primer, Bijan and I could "fix" it.

Additional other business

Peter Patel-Schneider: Agenda amendment: RIF statement on OWL compatibility

Peter Patel-Schneider: Possibly interesting to members of this group, please read if you are interested in the topic.