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AIList Digest Volume 3 Issue 167
AIList Digest Monday, 11 Nov 1985 Volume 3 : Issue 167
Today's Topics:
Seminars - TI AI Symposium Sites &
Model Theory for Knowledge and Belief (SRI) &
Example-Based Reasoning (NU) &
Knowledge Representation (UCB) &
Partial Truth Conditions and Their Logics (CSLI) &
Automatic Generation of Graphical Presentations (CSLI) &
CommonLoops (MIT) &
Minimal Entailment (UPenn) &
Alternatives to Concurrent Prolog (MIT),
Conference - Eastern Simulation Conference
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Date: Fri, 8 Nov 85 00:09 EST
From: Tim Finin <Tim%upenn.csnet@CSNET-RELAY.ARPA>
Subject: TI AI Symposium Sites
Two sites in our area that will be providing the TI AI Symposium are:
University of Pennsylvania
Harrison Auditorium (in the Univ. Museum, 33rd & Spruce)
Philadelphia, PA
contact: Tim Finin, TIM@UPenn (215-386-1749)
lots of room - all are welcome - no invitation/RSVP needed
U.S. Army Communications /Automatic Data Processing Center
Watters Hall
Fort Monmouth, NJ
contact: Ms. Van dyke (201-544-2929)
arrive early to assure seating.
It starts at 9:15 (EST) on Wednesday, November 13th.
------------------------------
Date: Wed 6 Nov 85 17:41:42-PST
From: LANSKY@SRI-AI.ARPA
Subject: Seminar - Model Theory for Knowledge and Belief (SRI)
MODEL THEORY FOR KNOWLEDGE AND BELIEF
Moshe Vardi
IBM San Jose
11:00 AM, MONDAY, November 11
SRI International, Building E, Room EJ228 (new conference room)
Recently, there has been a surge of interest in the modal logic of
knowledge and belief, which has applications in many area of computer
science. The standard semantics for modal logic is Kripke semantics.
In this semantics, possible worlds and the possibility relation are both
primitive notions. This has both technical and conceptual shortcomings.
>From a technical point of view, the mathematics associated with Kripke
semantics is often quite complicated. From a conceptual point of view,
it is not clear how to use Kripke structures to model knowledge and belief,
where one wants a clearer understanding of the notions that are taken as
primitive in Kripke semantics.
We introduce modal structures as models for modal logic. We use the idea
of possible worlds, but by directly describing the internal semantics of
each possible world. It is much easier to study the standard logical
questions, such as completeness, decidability, and compactness, using
modal structures. Furthermore, modal structures offer a much more
intuitive approach to modelling knowledge and belief.
As an application, we present a semantic model for knowledge
with the following properties:
(1) Knowledge is necessarily correct
(2) agents are logically omniscient, i.e., they know all
the consequences of their knowledge
(3) agents are positively introspective, i.e., they are aware of
their knowledge, but not negatively introspective,
i.e., they may not be aware of their ignorance.
We argue that this is the appropriate model for implicit knowledge.
We investigate the properties of the model, and use it to formalize
notions such as "to know more" and "all that is known is".
------------------------------
Date: Wed, 6 Nov 85 14:53 EDT
From: Carole D Hafner <HAFNER%northeastern.csnet@CSNET-RELAY.ARPA>
Subject: Seminar - Example-Based Reasoning (NU)
College of Computer Science Colloquium
Northeastern University, Boston, MA
Example-Based Reasoning
Prof. Edwina Rissland
Dept. of Computer and Information Science
University of Massachusetts, Amherst, MA
In this talk, I shall discuss example-based reasoning,
particularly in the contexts of assisting in the preparation of
legal arguments and offering on-line explanations.
In the case of legal argumentation, I discuss how hypotheticals
serve a central role in analyzing the issues in
a case and describe a program, called HYPO, which generates
legal hypotheticals, and an environment, called COUNSELOR,
which provides support for legal reasoning and other strategic
tasks, like resource management. I'll briefly describe our
current work on on-line assistance and how we are trying to
make it more intelligent by embedding custom-tailored examples
in the explanations. I'll also discuss some general issues
about examples such as their generation, structure and importance
in reasoning, especially in the domains of mathematics and the law.
Date: Wednesday, Nov. 13, 1985
Time: 12:00 noon
Place: To be announced (contact hafner@northeastern or call the
department office at 437-2462).
------------------------------
Date: Thu, 7 Nov 85 17:29:20 PST
From: admin%cogsci@BERKELEY.EDU (Cognitive Science Program)
Subject: Seminar - Knowledge Representation (UCB)
BERKELEY COGNITIVE SCIENCE PROGRAM
Cognitive Science Seminar - IDS 237A
Tuesday, November 12, 11:00 - 12:30
240 Bechtel Engineering Center
Discussion: 12:30 - 1:30 in 200 Building T-4
``Knowledge Representation and a Theory of Meaning''
Robert Wilensky
Computer Science Division, U.C.B.
Knowledge representation is central to most Artificial Intelli-
gence endeavors. However, most knowledge representation
schemes are incomplete in a number of ways. In particular,
their coverage is inadequate, and they do not capture signifi-
cant aspects of meanings. Many do not even adhere to basic
criteria of well-formedness for a meaning representation.
KODIAK is a theory of knowledge representation developed at
Berkeley that attempts to address some of these deficiencies.
KODIAK incorporates representational ideas that have emerged
from different schools of thought, in particular from work in
semantic networks, frames, Conceptual Dependency, and frame
semantics. In particular, KODIAK eliminates the frame/slot
distinction found in frame-based languages (alternatively,
case/slot distinction found in semantic network-based systems).
In its place KOKIAK introduces a new notion called the
absolute/aspectual distinction. In addition, the theory sup-
ports ``non-literal'' representations, namely, those motivated
by metaphoric and metonymic considerations. Using these dev-
ices, the theory allows for the representation of some ideas
that in the past have only been represented procedurally,
informally, or not at all.
KODIAK is being used to represent both linguistic and concep-
tual structures. When applied to the representation of
linguistic knowledge, a new framework for talking about meaning
emerges. Five aspects of meaning have been identified. These
appear to be useful in describing processing theories of
natural language use.
------------------------------
Date: Thu 7 Nov 85 16:41:45-PST
From: Emma Pease <Emma@SU-CSLI.ARPA>
Subject: Seminar - Partial Truth Conditions and Their Logics (CSLI)
[Excerpted from the CSLI Newsletter by Laws@SRI-AI.]
CSLI ACTIVITIES FOR *NEXT* THURSDAY, November 14, 1985
4:15 p.m. CSLI Colloquium
Redwood Hall Partial Truth Conditions and Their Logics
Room G-19 Hans Kamp, University of Texas
Partial Truth Definitions and their Logics
Hans Kamp
Until recently truth definitions for formal and natural languages
were, with some few exceptions, total (in the sense of specifying
w.r.t. any model a truth value for each sentence of the language under
consideration). But during the past decade partial truth definitions
have become increasingly common both within symbolic logic and in
formal semantics.
The motives for adopting partial truth definitions vary considerably.
I will focus on three issues that have led to the formulation of such
definitions: i) vagueness; ii) the semantic paradoxes; and iii)
verification by partial information structures (a concept that has
inspired both situation semantics and recent work on the semantics of
data structures). I will discuss and compare some of the partial
semantics that have been developed in attempts to come to terms with
these issues, looking in particular at the question what logics are
generated by the resulting semantic theories. I will argue that the
relation between semantics and logic is less straightforward when the
truth definition is partial than when it is total, and consequently that
the notion of logical validity becomes much more delicate and equivocal
once total semantics is abandoned in favor of some partial alternative.
------------------------------
Date: Thu 7 Nov 85 16:41:45-PST
From: Emma Pease <Emma@SU-CSLI.ARPA>
Subject: Seminar - Automatic Generation of Graphical Presentations (CSLI)
[Excerpted from the CSLI Newsletter by Laws@SRI-AI.]
PIXELS AND PREDICATES
Automatic Generation of Graphical Presentations
Jock Mackinlay
CSLI trailers, 1:00 p.m., Wednesday, November 13, 1985
The goal of my thesis research is to develop an application-
independent presentation tool that automatically generates appropriate
graphical presentations of information such as charts, maps, and
network diagrams. A presentation tool can be used to build effective
user interfaces because it exploits the structure of the information
and the capabilities of the output device to generate appropriate
presentations. Application designers need not be graphical
presentation experts to ensure that their user interfaces use
graphical languages correctly and effectively.
The research has two parts: a formal analysis of graphical
languages for presentation and a prototype presentation tool based on
the formal analysis.
The formal analysis uses syntactic and semantic descriptions of
graphical languages to develop criteria for evaluating graphical
presentations. There are two major classes of criteria: expressiveness
and effectiveness. The expressiveness criteria are theorems that identify
when a set of facts is or is not expressible in a language. The
effectiveness criteria are conjectures (rather than theorems) about
the relative difficulty of the perceptual tasks associated with the
interpretation of graphical languages. Sufficiently expressive languages
are ordered by the difficulty of their associated perceptual tasks.
The prototype presentation tool, called APT (A Presentation Tool),
uses the criteria developed by formal analysis to search a space of
graphical languages for an appropriate presentation. A novel feature
of APT is its ability to generate its search space by composing
sophisticated designs from a small set of fundamental graphical
languages. The design portion of APT is a logic program based on the
MRS representation system.
------------------------------
Date: Thu 7 Nov 85 15:32:51-EST
From: "Mary E. Spollen" <SPOLS%MIT-OZ@MIT-MC.ARPA>
Subject: Seminar - CommonLoops (MIT)
[Forwarded from the MIT bboard by SASW@MIT-MC.]
CommonLoops
Speaker: Gregor Kiczales
Xerox Palo Alto Research Center
Date: November 15, 1985, Friday
Time: 2:15 refreshments
2:30 lecture
Place: NE43-512A
CommonLoops is a merger of Object Oriented Programming and Lisp. It
has a unique combination of features:
1) No special syntax: Most attempts to add object-oriented programming
to Lisp have resulted in special syntax for message sending. In
CommonLoops, there is no syntactic difference between calling a function
and "invoking a method."
2) Method Specification: In object oriented programming, methods are
specified in terms of the class of the object being sent the message.
One can think of this as specifying the type of one argument of the
method. In CommonLoops, one can specify the type of any number of
arguments to a method.
3) Type space: The "object" space is an extension of the normal Lisp
type space, not a separate space as in Loops or Flavors.
4) Metaclasses: The implementation of a type (determined by the
"metaclass") is independent of the type description. This allows
tradeoffs between early binding and ease of exploratory programming.
Host: Hal Abelson
------------------------------
Date: Sat, 9 Nov 85 00:53 EST
From: Tim Finin <Tim%upenn.csnet@CSNET-RELAY.ARPA>
Subject: Seminar - Minimal Entailment (UPenn)
FUN WITH MODELS: MINIMAL ENTAILMENT AND NON-MONOTONIC REASONING
David W. Etherington
University of British Columbia
(Currently at AT&T Bell Laboratories, Murray Hill, NJ.)
3:00pm December 3, 1985
216 Moore School, University of Pennsylvania, Philadelphia
Circumstances commonly require that conclusions be
drawn (conjectured) even though they are not strictly war-
ranted by the available evidence. Various forms of minimal
entailment have been suggested as ways of generating
appropriate conjectures. Minimal entailment is a conse-
quence relation in which those facts which hold in minimal
models of a theory are considered to follow from that
theory. Thus minimal entailment is less restrictive than
the standard logical entailment relation, which strongly
constrains what evidence may be taken as supporting a con-
clusion.
Different definitions of minimality of models yield
different entailment relations. The talk will outline a
variety of such relations. Domain, Predicate, and Formula
Circumscription [McCarthy 1978, 1980, 1984] are syntactic
formalisms intended to capture these relations. We examine
each from a semantic viewpoint, in the hope of clarifying
their respective capabilities and weaknesses. Results on
the consistency, correctness, and adequacy of these formal-
isms will be presented.
While minimal entailment corresponds most directly to
the Closed-World Assumption, that positive information not
implicit in what is known can be assumed false, McCarthy and
others have suggested applications of circumscription to
more general default reasoning tasks. With this in mind,
connections between minimal entailment and Reiter's Default
Logic will be sketched, if time permits. In this connec-
tion, we will consider positive and negative results due to
Grosof and Imielinski, respectively.
------------------------------
Date: Sun, 10 Nov 85 00:56:01 EST
From: "Steven A. Swernofsky" <SASW@MIT-MC.ARPA>
Subject: Seminar - Alternatives to Concurrent Prolog (MIT)
Thursday 7, November 2: 15pm Room: NE43- 7th floor playroom
BFCP and GHC - Alternatives to Concurrent Prolog
Jacob Levy
Department of Applied Mathematics
Weizmann Institute of Science
This talk will discuss some of the alternatives to Concurrent Prolog
recently proposed. Each of these languages is designed to cover a
large subset of Concurrent prolog, but to be much easier to implement.
Flat Concurrent prolog (FCP) and Guarded Horn Clauses (GHC) will be
described in detail.
FCP, which has only And-parallelism, was developed at the Weizmann
Institute as a viable subset of Concurrent Prolog. Its current
implementation, in terms of a Warren Abstract Machine, will be
described.
The GHC language, designed by K. Ueda of ICOT, Japan, has
OR-parallelism as well as And-parallelism, but instead has more
limited synchronization primitives than Concurent Prolog. The second
part of this talk will briefly describe my implementation of GHC.
After the talk, a demo of FCP and Logix, its programming environment,
will be given.
Refreshments at 2:00pm
HOSTS: Professors Gerald Jay Sussman and Henryk Jan Komorowski (Harvard)
------------------------------
Date: 1 Nov 1985 17:09-CST
From: leff%smu.csnet@CSNET-RELAY.ARPA
Subject: 1986 Eastern Simulation Conference
10-12 March 1986, Omni International Hotel, Norfolk, Virginia
For more info contact: SCS, PO BOX 17900, San Diego, CA 92117
(619)277-3888
List of AI related titles:
"TAT Teach" An Expert Training Simulator
Knowledge-Based Opponent Simulation for Tactical Decision Training
Simulators with Artificial Intelligence
Expert Systems in Training/Decision/Simulation
The Simulation Algorithm Itself: Driving the Inference Algorithm
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End of AIList Digest
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