Joint Committee Minutes 26 June 2001

This page summarizes the telecon for the Joint US/EU Committee on Agent Markup Languages held from 1300 to 1400 PDT on 26 June 2001. These minutes were prepared by the chairman, and were approved during the 3 July telecon.

Participants

Announcements

The SWWS agenda is being finalized A registration site is now available; a high turnout is expected, so register soon! Eric Miller will give an invited talk on the W3C Semantic Web Activity.

Previous Week's Minutes

The minutes from June 5, June 12, and June 19 were approved by those present.

Coordination between RDF(S) and DAML+OIL

We discussed Peter's message.

Ian noted that DAML+OIL requires that both subclass and subproperty can be reflexive.

DAML+OIL does use metaclasses (rdfs:Class and rdfs:Property are essentially both classes and metaclasses) as a syntactic device to define our classes (e.g. DatatypeProperty), but metaclasses are not addressed in the semantics.

We were unsure what "fit in the middle" referred to.

This list doesn't address XML syntax. We've received considerable feedback that the current syntax is good for machines, but not for humans. We may want to also relate our observations about ID/about and the inability to use namespaces in attribute values.

We may want to separate the "data types" issue into 2 issues: XML Schema builtin datatypes (now in DAML+OIL) and derived and complex data types (not directly addressed by DAML+OIL).

In addition to "RDF gives meaning to all syntax" (although rdf:parseType provides some extensibility), RDF also gives meaning to all triples.

ACTION (Frank): update Peter's list based on our discussion

Face-to-Face Meeting

We will plan to meet from 2-8pm at the Nashua Marriott in a conference room or suite with Internet connectivity.

The following people have indicated their plans to attend:
Dan Connolly no
Mike Dean yes
Frank van Harmelen no
Pat Hayes yes, but arriving late
Ian Horrocks yes
Deb McGuinness yes
Peter Patel-Schneider no (may call in)
Lynn Andrea Stein yes (2-5pm)

Collections as Properties

We discussed Jim's message. We concluded that Jim wants ordering and (presumably) to be able to use DAML+OIL's rdf:parseType="daml:collection" list syntax to specify values.

This is related to Dan Connolly's setOf and listOf properties.

Note that daml:first (and daml:rest) used by daml:List is defined as an rdf:Property, not daml:ObjectProperty or daml:DatatypeProperty, limiting the semantics associated with daml:List.

Ian discussed a technique for preventing cycles in lists (modulo an issue with pure, disconnected cycles), and subsequently provided a more detailed example (which also includes a ListC class that addresses Jim's problem).

Updates to Axiomatic Semantics

We discussed the findings of applying ConsVISor and Specware to the DAML+OIL axiomatic semantics.

Deb and Richard Fikes had received email about most of these issues as they were discovered. They are working on fixes to the axiomatic semantics as part of an upcoming DAML+OIL paper for IEEE Intelligent Systems (which is an update to the DAML-ONT paper published in the MIT Web Semantics book), but probably won't get to finish this for at least 2 months. This will also include several fixes from other sources.

RESOLVED: We will add these updated semantics to the DAML+OIL (March 2001) page, alongside the initial version for this language release.

Next Week

Ian (and possibly others) will report on discussions with the DAML-S Coalition on their use of DAML+OIL. DAML-S 0.5 somewhat "underutilizes" DAML+OIL, focusing primarily on RDFS constructs.

Stefan and Pat will plan to introduce their rules proposal.

Links

IRC
last week's minutes
Joint Committee home page

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