AIList-REQUEST@SRI-AI.ARPA (AIList Moderator Kenneth Laws) (12/20/85)
AIList Digest Friday, 20 Dec 1985 Volume 3 : Issue 190 Today's Topics: Seminars - Example-Based Reasoning (UPenn) & Clausal Intuitionistic Logic (UPenn) & Robot Control with Kinesthetics (UPenn) & HORNLOG: Horn Clause Logic with Graph Rewriting (UPenn), Course - Deduction and Computation (CMU) & Symbolic Computation (UTexas) ---------------------------------------------------------------------- Date: Tue, 17 Dec 85 09:50 EST From: Tim Finin <Tim%upenn.csnet@CSNET-RELAY.ARPA> Subject: Seminar - Example-Based Reasoning (UPenn) 3pm Tuesday, December 17, 1985 Room 216 Moore School University Of Pennsylvania EXAMPLE-BASED REASONING EDWINA L. RISSLAND, HARVARD 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: Tue, 17 Dec 85 09:50 EST From: Tim Finin <Tim%upenn.csnet@CSNET-RELAY.ARPA> Subject: Seminar - Clausal Intuitionistic Logic (UPenn) 3pm Thursday, December 19, 1985 Room 216 Moore School University of Pennsylvania FIXED POINT SEMANTICS AND TABLEAU PROOF PROCEDURES FOR A CLAUSAL INTUITIONISTIC LOGIC L. THORNE MCCARTY COMPUTER SCIENCE DEPARTMENT RUTGERS UNIVERSITY Since the advent of Horn clause logic programming in the mid-1970's, there have been numerous attempts to extend the expressive power of Horn clause logic while preserving some of its attractive computational properties. This talk will present a clausal language which extends Horn clause logic by adding negations and embedded implications to the right hand side of a rule, and which interprets these new rules intuitionistically, in a set of partial models. The resulting system will be shown to have a fixed point semantics which resembles the fixed point semantics of Horn clauses, and a tableau proof procedure which generalizes Horn clause refutation proofs. Soundness and Completeness results will also be presented. Finally, the talk will outline some connections between this clausal intuitionistic logic and several familiar forms of non-monotonic reasoning. ------------------------------ Date: Thu, 19 Dec 85 14:10 EST From: Tim Finin <Tim%upenn.csnet@CSNET-RELAY.ARPA> Subject: Seminar - Robot Control with Kinesthetics (UPenn) Ph.D. Dissertation Proposal Presentation 3:00pm Friday, Dec. 20, 1985 554 Moore School University of Pennsylvania ROBOT CONTROL WITH KINESTHETICS: A REAL TIME EXPERT SYSTEM Russell L. Andersson The utility of robots is directly determined by the activities they can perform and the speed with which they can perform them. The purpose of this research is to develop means to improve the performance of robots, both in speed and especially in functionality. We maintain that the robots are already being limited by their controllers; rather than redesign the robot itself, we address the problem of how to improve the controller. Our approach is to create a sense of kinesthetics: to make more information about the robot available to the controller, and to find ways to use it. Kinesthetics requires operation in both the numeric and symbolic domains, so the system must be capable of using and interconverting both domains. We propose an expert system and a means to compile it to a form executable in real time. ------------------------------ Date: Thu, 19 Dec 85 14:10 EST From: Tim Finin <Tim%upenn.csnet@CSNET-RELAY.ARPA> Subject: Seminar - HORNLOG: Horn Clause Logic with Graph Rewriting (UPenn) Ph.D. Dissertation Proposal Presentation 3:00pm Friday, Dec. 20, 1985 554 Moore School University of Pennsylvania INVESTIGATIONS INTO HORNLOG: A HORN CLAUSE INTERPRETER BASED ON GRAPH REWRITING Stan Raatz HORNLOG, due to Jean Gallier, is a Horn clause proof procedure that can be used to interpret logic programs. The system is not resolution-based, but rather is based on a form of graph-rewriting and a linear-time algorithm for testing the unsatisfiability of propositional Horn formulae. HORNLOG applies to a class of logic programs which is a proper superset of the class of logic programs handled by PROLOG systems. In particular, negative Horn clauses used as assertions and queries consisting of disjunctions of negations of Horn clauses are allowed. This class of logic programs admits answers which are indefinite, in the sense that an answer can consist of a disjunction of substitutions. The method does not use negation by failure semantics in handling these extensions. In this proposal, using the HORNLOG procedure, we develop a theory and give examples of a type of logic programming called "general Horn clause programming. We give soundness and completeness results, show that the procedure has an immediate parallel interpretation, and argue that the method compares favorably with SLD-resolution in a parallel environment. In addition, two extensions are outlined: (1) the inclusion of term-rewriting to handle certain instances of equational programming, and (2) an uncertainty calculus for expert system applications. ------------------------------ Date: 16 Dec 1985 1005-EST From: Lydia Defilippo <DEFILIPPO@C.CS.CMU.EDU> Subject: Course - Deduction and Computation (CMU) [Forwarded from the CMU bboard by Laws@SRI-AI.] DEDUCTION AND COMPUTATION A Spring Seminar Proposal Gerard huet Course No.: 15-850B Starting Date: 9 January 1986 Tuesdays and Thursdays from 10:00 - 11:30 am Place: 5409 Wean Hall The seminar will consist in two distinct phases. The first phase will be a standard course, and will last 8 weeks. The topics covered include basics of proof theory, such as sequent calculus, equational logic, canonical rewriting and natural deduction, and foundations of applicative programming languages, such as lambda calculus, combinators, sequential computations, types and polymorphism. The course ends with a more advanced section on the Constructions Calculus. The course is completely self-contained, there is no pre-requisite. Course notes will be available. The second phase, for the remaining 6 weeks, will be an advanced seminar on the computer automation of constructive mathematics. The participants will group themselves in teams, and attempt to develop mechanical proofs of selected theorems on the implementation of the Constructions Calculus. A team may consist in 1 to 3 participants. It is expected that terms will balance mathematical and programming talents for maximum efficiency. Each team will have access to a computer running an implementation of the Constructions Calculus. The goal of the seminar is to produce a uniform document describing the results of the experiments. ------------------------------ Date: Tue 17 Dec 85 18:48:00-CST From: AI.HASSAN@MCC.ARPA Subject: Course - Symbolic Computation (UTexas) [Forwarded from the UTexas bboard by Laws@SRI-AI.] SYMBOLIC COMPUTATION Graduate Seminar Proposal CS395-T Spring 1986 Dr. Hassan Ait-Kaci This course is intended as a bridge between Theory and Practice. It will consist of a tutorial on symbolic computation models based on functional, algebraic, and logical calculi, as well as advanced state-of-the-art in next-generation programming language research. The main focus will be on explaining how some abstract concepts derived from Logic and Universal Algebra can be used to describe symbolic computation and data structures, and how these concepts may be implemented efficiently. During the course, many existing as well as original experimental examples will be scrutinized in detail. TENTATIVE OUTLINE 1. Mathematics for Symbolic Computation a. Lambda-Calculus b. Universal Algebra c. Predicate Logic 2. Functional Computation a. Applicative Programming b. Interpreting the Lambda-Calculus c. Compiling the Lambda-Calculus (SECD Machine) d. Extensions i. Delayed-Evaluation and Streams ii. Non-Deterministic Computations iii. Binding by Unification 3. Algebraic Computation a. Term Rewriting b. Knuth-Bendix Completion Method c. Rewriting Termination d. Resolution of Equations (Narrowing, Congruence Closure) e. Equational Logic Programming 4. Logic Computation a. Horn Clause Resolution b. Compiling Horn Clause Resolution c. Extensions i. Building-In Equations ii. Building-In Inheritance iii. Non-Horn Logic Programming iv. Higher-Order Logic Programming 5. Unifying Principle: The Categorical Abstract Machine 6. Data Types a. Algebraic Abstract Data Types b. Polymorphic Types (Universal and Existential) c. Constructive Type Theory PREREQUISITE: Although meant to be self-contained, this course will offer optimal benefit to anyone acquainted with senior-level discrete mathematics and computer programming. The only *real* prerequisite is an open mind. PARTICIPATION: Students will be expected to participate actively in presentations of assigned readings, implementation of experimental programs, and in completing either a term paper or a programming project. TEXT: Most of the material covered will be taken from articles, and extensive notes written by the instructor. A (far from exhaustive) list of recommended books would be (1) Burge's "Recursive Programming Technique", (2) Henderson's "Functional Programming" (3) Campbell's (Ed.) "Implementations of Prolog", as well as anything else related to the outlined topics. ENROLLMENT: This course will be given only if at least 5 students register. Anybody interested in *registering* is encouraged to contact Hassan Ait-Kaci at 834-3354, ARPA address "Hassan@mcc", AS SOON AS POSSIBLE! ------------------------------ End of AIList Digest ********************