AIList-REQUEST@SRI-AI.ARPA (AIList Moderator Kenneth Laws) (11/11/85)
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 ---------------------------------------------------------------------- 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 ------------------------------ End of AIList Digest ********************