Three-Values
Logic and Non-Monotonic Reasoning
N.
Obeid
Abstract.
In this paper we present a three-valued logical system T3
which is both sound and complete with respect to a class X
partial models. We show that T3:
(1) subsumes Gabbay's system m
and (2) makes a distinction between two modal notions: epistemic
possibility and plausibility. We
then extend the class X
and present Modal-T3 logics: K-T3, T-T3, S4-T3,
and S5-T3. which are then analogue of standard modal logics K, T, S4 and S5
and show that all these systems are sound and complete. We also show that the
explicit default operator D of Doherty
[5] and of Doherty and Lukaszewicz [6] is definable in Modal-T3
and autoepistemic models [40, 41] are just a particular case of partial models
modal structures.
Multilanguage
Interoperability
G.
Attardi, M. Gaspari
Abstract.
We present an approach to the interoperability of programming languages, based
on a Common Runtime Support (CRS), which provides general mechanisms for storage
management, symbol table management and concurrent execution, for modern high
level languages. We focus in particular on the CRS approach to the
interoperability of AI languages, in particular Prolog and Common
Lisp. The CRS provides support for logic variables, so that both a Lisp
Abstract Machine and a subset of the Warren Abstract Machine, including all the
unification primitives, are implemented on it. We present and compare two
alternative implementations of non/determinism and backtracking, through success
continuations and failure continuations. Both Lisp and Prolog programs are
compiled to C code to run on the C/based CRS. The interoperability is achieved
with minimal overhead and this allows programmers to select the most appropriate
programming paradigm for each task: functional, logic and object-oriented.
Finally, we show how an efficient theorem prover for first order predicates can
be implemented on the CRS obtaining interesting performances.
A
Refinement of Communicating Processes
S.
Damy, G.-R. Perrin
Abstract.
The programming of MIMD multiprocessors requires to design processes to be
mapped on the nodes of the architecture and communicating by message passing.
The aim of this paper is to give a contribution for a rationalized design of
such programs from formal specifications. We introduce a refinement calculus of parallel specifications in which processes refine the safety
properties and communications refine the liveness one. Rules and the stepwise
technique are illustrated by the shortest path problem.
Primer-Field
Complete Functions and Factoring Polynomials over Finite
Fields
L.
Rónyai, A. Szántó
Abstract.
We relate the arithmetic straight-line complexity over a field GF(p) (p is a prime) of
the parity function lp to
the Boolean complexity of the problem of factoring polynomials over finite
fields of characteristic p. A
procedure is described which converts an arithmetic straight-line program for lp
into a factoring algorithm.
As a consequence, a short straight-line program for lp
would imply the existence of an efficient factoring method.
A
Parallel Algorithm to Compute the Supremum of Max-Min Powers
F.
Suraweera, P. Bhattacharya
Abstract.
We present a parallel algorithm to compute the supremum of max-min powers of any
map from the Cartesian product of a finite set to a bounded subset of the real
numbers which can be run on an SIMD machine. The algorithm is based on graph
theoretical methods. Some variations of the parallel algorithm are also
considered.
Artificial
Intelligence: Conceptual Status and Applications
I.V.
Ezhkova