Ontolog Forum

Ontolog invited Speaker Presentation - Dr. Pat Hayes - Thu 2006-10-26

Conference Call Details

  • Subject: Ontolog Invited Speaker Presentation by Pat Hayes - Thu 2006-10-26
  • Agenda: Dr. Pat Hayes from the Florida Institute for Human & Machine Cognition ("IHMC") will be presenting to the community his talk entitled: "A logic for ontology interoperation"
  • Date: Thursday, October 26, 2006
  • Start Time: 17:30 UTC / 6:30pm BST / 1:30pm EDT / 10:30am PDT
    • see world clock for other time zones)
    • Duration: 1.5~2.0 hours
  • Dial-in Number: +1-641-696-6600 (Iowa, USA)
    • Participant Access Code: "686564#"
  • Presentation: click here for Dr. Hayes' slides. He'll be prompting everyone to advance slides during the talk.
  • Shared-screen support (VNC session) will be started 5 minutes before the call at:
    • view-only password: "ontolog"
    • if you plan to be logging into this shared-screen option (which the speaker may be navigating), and you are not familiar with the process, please try to call in 5 minutes before the start of the session so that we can work out the connection logistics. Help on this will generally not be available once the presentation starts.
    • people behind corporate firewalls may have difficulty accessing this. If that is the case, please download the slides below and runing them locally. The speaker will prompt you to advance the slides during the talk.
  • RSVP to This will help us prepare enough conferencing resources. Kindly include your name, affiliation, title and location, if you aren't already a registered member of Ontolog.
  • Please note that this session will be recorded, and the audio archives is expected to be made available as open content to our community membership and the public at-large under our prevailing open IPR policy.


  • Others we were expecting that didn't get into the roll call (mainly because we had problems with the conference phone line at the beginning of the session, and participants had to log out and log back in more than once):
    • ...(to register for participation, please add your name (plus your affiliation, if you aren't already a member of the community) above, or e-mail <> so that we can reserve enough resources to support everyone's participation.)...

Agenda & Proceedings

  • Invited Speaker Dr. Pat Hayes from the Florida Institute for Human & Machine Cognition ("IHMC") will be presenting to the community his talk entitled: "A logic for ontology interoperation"
[picture of Dr. Pat Hayes]
Abstract: (by PatHayes)
Over the past few years a series of initiatives have converged on the design of a 'common logic' into which a large variety of alternative logical notations and formalisms can be projected, and so can act as an expressive foundation for ontology interchange and standardization. This talk will briefly survey the design principles that have emerged from these discussions and the outline of the resulting framework, which is currently going through ISO approval as ISO Common Logic, and a more recent extension called IKL, designed explicitly for ontology interoperation, which provides a variety of powerful naming conventions which enable it to explicitly describe relationships between ontological frameworks. We will illustrate the talk with examples showing how description logics such as OWL, modal and temporal logics, hybrid logics and context logics can be mapped into CL and IKL.
  • Session Format and Agenda:
    • this will be virtual session over a phone conference setting, augmented by shared computer screen support
    1. The session will start with a brief self-introduction of the attendees (~10 min.) [We will be skipping this if there are more than 20 participants.]
    2. Introduction of the invited speaker by Professor Chris Menzel
    3. Presentation by our invited speaker Dr. Pat Hayes (45~60 min.)
    4. Q&A and Open discussion (30~45 min.) [Kindly identify yourself before speaking.]
  • Auto Bio of our Speaker - Dr. Pat Hayes:
I hold a meaningless job title at the Florida IHMC, a smallish interdisciplinary research center located on the Gulf Coast, where the superb seafood more than makes up for an occasional hurricane. I am currently a member of the W3C Data Access Working Group tasked with the design of an RDF/OWL query language. I have been at various times an AI researcher, a Luce Professor of cognitive science, a Professor of philosophy, a notational engineer and a Semantic Web researcher. The common thread running through all this is an enduring interest in how informal knowledge can be formalized, and in the actual semantic machinery of formalization itself. My work that is of most interest to ontologists is probably, in order: one of the first attempts to use formal logic to describe everyday physical knowledge, in a series of papers on "Naive Physics" published in the 1980s; a series of papers on temporal ontologies, culminating in one of the first thorough comparative surveys; and more recently, contributions to the writing of new 'standard' logics, including the W3C semantic web ontology standard sequence RDF/RDFS/OWL and the ISO Common Logic draft standard; and most recently, the IKL logic developed with Chris Menzel and others. This recent work has strengthened my long-standing belief that formal logic (and philosophy more generally) should be the servant of a pragmatic approach to writing ontologies: a valuable servant, but not the master. For example, the pragmatic requirements of publishing formal content on an 'open' Web seem to require us to re-examine several unspoken assumptions in the foundations of logic which have become widely accepted without being subjected to critical examination. Rather than trying to force the world to use textbook logic, we have chosen to rebuild the foundations.
Other interests include what is often called "logical AI", which is of course closely related to ontology design, the philosophical foundations of cognitive science, and the analysis of consciousness (which itself, I believe, is closely related to how we perceive the "passage of time" - a phrase which is physically meaningless yet intuitively compelling.)

logic. It is not a single syntax: particular conforming syntaxes are called dialects. CL allows for a wide variety of surface syntax forms. CL syntax is unusually 'free', allowing a wide variety of expressions, and extends the semantics appropriately.

      • CLIF is one particular CL syntax, very 'lisp-like', modeled closely on KIF

(though not identical). For more on CL and CLIF, see the ISO draft standard (available at Please do not cite until final ISO approval.) Many of the examples in this talk are written in CLIF syntax.

      • KIF is a venerable early 'standard' logic, the ancestor of CL. CLIF is very similar

to a subset of KIF. Historically, the KIF project was the precursor of all the rest of this stuff, and many of the same people were involved. See

      • IKL is a recent extension of CL, very similar to CLIF, not yet 'standard' but in

active use. This talk will focus on IKL, but will illustrate a lot about CLIF, and hence about CL, along the way. Development of IKL was supported by ARDA under the IKRIS program. For more on IKL, including many examples, see

  • If you have questions for the presenter, we appreciate your posting them here: (please identify yourself)
    • ... (post you questions here, the speaker will be fielding them during the open discussion session) ...< For some answers, see >
    • I have a couple of questions regarding IKL; however, I can only attend the first part of the conference. So it is OK for me to answer them later, but perhaps they are interesting for the conference as well. Till Mossakowski
      • is there a (complete) calculus for IKL?
      • are there tools for IKL (parser, inference engine)?
      • is it possible to efficiently typechek formulas with an inference engine? (i.e. given that type information is coded via predicates somehow)
      • I do not get the point of (that p). In the IKL guide, it is claimed that IKL is compositional. But then, |= (iff p q) implies I(p)=I(q), which in turn implies I(that p)=I(that q), which implies |= (= (that p) (that q)), which means that there are really only two propositions, namly (that false) and (that true).
      • I do not understand captured names either. On the slides, it is claimed that they map contexts to referents. In the IKL specification, I did not find anything about contexts. I did not find semantic clauses that helped me to interpret ('<string>') either.
  • For those who have further questions for Pat Hayes, please post them to the ontolog forum so that we can all benefit from the discourse.
  • Session ended 2006-10-26 12:40 pm PDT

Session Recording of the Pat Hayes Talk

(Thanks to Bob Smith and Peter P. Yim for their help with getting the session recorded. =ppy)

  • To download the audio recording of the presentation, click here
    • the playback of the audio files require the proper setup, and an MP3 compatible player on your computer.
  • Conference Date and Time: October 26, 2006 10:48am~12:40pm Pacific Daylight Time
  • Duration of Recording: 1 Hour 50 Minutes
  • Recording File Size: 12.9 MB (in mp3 format)
  • Telephone Playback Expiration Date: November 5, 2006 12:56 PM Pacific Time
    • Prior to the above Expiration Date, one can call-in and hear the telephone playback of the session.
    • Playback Dial-in Number: 1-805-620-4002 (Ventura, CA)
    • Playback Access Code: 317865#
    • suggestions:
      • its best that you listen to the session while having the presentation opened in front of you. You'll be prompted to advance slides by the speaker.