181.
Assigning an appropriate meaning to database logic with negation
- Je Rey D. Ullman
Deductive database systems | that is, database systems with a query language based on logical rules | must allow negated subgoals in rules to express an adequate range of queries. Adherence to classical deductive logic rarely o ers the intuitively correct meaning of the rules. Thus,avariety of approaches to de ning the \right" meaning of such rules have been developed. In this paper we survey the principal approaches, including strati ed negation, well-founded negation, stable-model semantics, and modularly strati ed semantics. 1.
182.
A Proof-Theoretic Framework for Logic Programming
- Gerhard Jager,Robert F. Stark,Rue Faucigny
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Basic notions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 Some model-theoretic properties of logic programs . . . . . . . . . . . . . . 13
4 Deductive systems for logic...
183.
A Proof-Theoretic Framework for Logic Programming
- Gerhard Jäger; Robert F. Stärk
Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Basic notions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 Some model-theoretic properties of logic programs . . . . . . . . . . . . . . 13 4...
184.
Why Probability Does Not Capture the Logic of Scientific Justification
Here is the usual way philosophers think about science and induction. Scientists do many things — aspire, probe, theorize, conclude, retract, and refine — but successful research culmi-nates in a published research report that presents an argument for some empirical conclusion. In mathematics and logic there are sound deductive arguments that fully justify their conclu-
185.
A sequent calculus for bilattice-based logic and its many-sorted representation
- Ekaterina Komendantskaya
Abstract. We introduce a sequent calculus for bilattice-based annotated logic (BAL). We show that this logic can be syntactically and semantically translated into a fragment MSL ∗ of conventional many-sorted logic MSL. We show deductive equivalence of sequent calculus for BAL and sequent calculus for MSL ∗. 1
186.
Models of Abduction – From an Interrogative Viewpoint
- Gerhard Schurz
In this paper I will discuss models of abduction from an interrogative viewpoint. However, my interrogative viewpoint will not be as radical as the interrogative logic of inquiry developed by Jakkoo Hintikka and his collaborators. Hintikka's interroga-tive logic (1998, Hintikka et al. 2000) starts from the assumption that all newly ac-quired information in scientific discovery must be obtained from a reliable informa-tion source. This source is abstractly viewed as an oracle which gives answers to our questions. In scientific discovery, the ultimate oracle is nature itself − as it presents itself in observations or controlled experiments. Therefore, in Hintikka's interrogative...
187.
HiLog: A Foundation for Higher-Order Logic Programming
- Weidong Chen,Michael Kifer,David S. Warren
We describe a novel logic, called HiLog, and show that it provides a more suitable basis for logic programming than does traditional predicate logic. HiLog has a higher-order syntax and allows arbitrary terms to appear in places where predicates, functions and atomic formulas occur in predicate calculus. But its semantics is first-order and admits a sound and complete proof procedure. Applications of HiLog are discussed, including DCG grammars, higher-order and modular logic programming, and deductive databases. Keywords: logic programming, higher-order logic, contextual predicate calculus, first-order semantics, resolution theorem proving, database languages, object-oriented databases, modular programming, DCG grammars. 1 Preface Manipulating...
188.
Logic for Media - The Computational Media Metaphor
- Ulrike Lechner,Beat F. Schmid
: New media as they are established by information
and communications technology demand for
reconsidering the notion of a medium as a carrier of
information and with it the concepts for representation,
organization, processing and dissemination of information.
We explore a general model for media, the
Computational Media Metaphor and utilize Rewriting
Logic and Labelled Deductive Systems to model media.
We obtain a general description of media according to
which the medium can be built as well as a generic media
architecture. Our example is the NetAcademy, a
computational medium for the scientific community.
Keywords: Medium, Multi Agent System, Labelled
Deductive System, Rewriting Logic
I. Introduction
Information technology has been changing the notion
of a medium...
189.
The Case for an Inductive Computing Science
- Derek Partridge
In the past few decades a science of computing has begun to emerge from the conglomeration
of ad hoc techniques, and partially understood principles that governed the
production of software once it became a widespread activity. Great strides forward in
hardware technology have outstripped the relatively slow development of a necessary,
complementary, software technology. However, early realization of this need for a science
to underpin software development has led to much effort towards producing it. A central
plank of the resultant formal infrastructure is logical deduction. It is almost axiomatic
within computing science proper that the basis for software science should be logic, and,
moreover, it should be...
190.
Antitonic Logic Programs
- Carlos Viegas Damasio,Lus Moniz Pereira
In a previous work we have de ned Monotonic Logic Programs which extend definite logic programming to arbitrary complete lattices of truth-values with an appropriate notion of implication. We have shown elsewhere that this framework is general enough to capture Generalized Annotated Logic Programs, Probabilistic Deductive Databases, Possibilistic Logic Programming, Hybrid Probabilistic Logic Programs and Fuzzy Logic Programming [3, 4]. However, none of these semantics define a form of non-monotonic negation, which is fundamental for several knowledge representation applications. In the spirit of our previous work, we generalise our framework of Monotonic Logic Programs to allow for rules with arbitrary...
191.
Antitonic Logic Programs
- Carlos Viegas Damasio; Luis Moniz Pereira
In a previous work we have de ned Monotonic Logic Programs which extend definite logic programming to arbitrary complete lattices of truth-values with an appropriate notion of implication. We have shown elsewhere that this framework is general enough to capture Generalized Annotated Logic Programs, Probabilistic Deductive Databases, Possibilistic Logic Programming, Hybrid Probabilistic Logic Programs and Fuzzy Logic Programming [3, 4]. However, none of these semantics define a form of non-monotonic negation, which is fundamental for several knowledge representation applications. In the spirit of our previous work, we generalise our framework of Monotonic Logic Programs to allow for rules with arbitrary...
192.
The Case for an Inductive Computing Science
- Derek Partridge; D. Michie; R. Johnston; The Creative Computer
In the past few decades a science of computing has begun to emerge from the conglomeration of ad hoc techniques, and partially understood principles that governed the production of software once it became a widespread activity. Great strides forward in hardware technology have outstripped the relatively slow development of a necessary, complementary, software technology. However, early realization of this need for a science to underpin software development has led to much effort towards producing it. A central plank of the resultant formal infrastructure is logical deduction. It is almost axiomatic within computing science proper that the basis for software science...
193.
Logic for Media - The Computational Media Metaphor
- Ulrike Lechner; Beat F. Schmid; Muller Friedberg Str; Muller Friedberg Str; Ch- St. Gallen; Ch- St. Gallen
: New media as they are established by information and communications technology demand for reconsidering the notion of a medium as a carrier of information and with it the concepts for representation, organization, processing and dissemination of information. We explore a general model for media, the Computational Media Metaphor and utilize Rewriting Logic and Labelled Deductive Systems to model media. We obtain a general description of media according to which the medium can be built as well as a generic media architecture. Our example is the NetAcademy, a computational medium for the scientific community. Keywords: Medium, Multi Agent System, Labelled...
194.
Uncertainty and Partial Non-Uniform Assumptions in Parametric Deductive Databases
- Yann Loyer; Umberto Straccia
Di#erent many-valued logic programming frameworks have been proposed to manage uncertain information in deductive databases and logic programming. A feature of these frameworks is that they rely on a predefined assumption or hypothesis, i.e. an interpretation that assigns the same default truth value to all the atoms of a program, e.g.
195.
[Ll] Lloyd: Foundations of Logic Programming, Springer, 1987. [LST] Lloyd, Sonenberg, Topor: Integrity constraint checking in stratified databases, J. Logic Programming 4, 1987. [LT] Lloyd, Topor: Making Prolog more expressive, J. Logic Programming 3, 198
- Kkt Kakas; Morgan Kaufmann
[Pr] Przymusinski: On the declarative semantics of deductive databases and logic programs; in [Mi], 1988. [Re1] Reiter: On closed world data bases, in Gallaire, Minker (eds), Logic and Data Bases, Plenum Press, 1978. [Re2] Reiter: Towards a logical reconstruction of relational database theory,
196.
Evaluation of Declarative N-Queens Recursion: A Deductive Database Approach
- Jiawei Ling,Liu Tong Lu
Can we evaluate a logic program declaratively? That is, can a logic program be evaluated correctly and
efficiently, independent of query modes and rule/predicate ordering, finding a complete set of answers, and
terminating properly? The answer could be "yes", at least for a good subclass of logic programs, based on our
investigation and experimentation using a deductive database approach. In this paper, an n-queens problem,
a classical logic program, is used as a running example to demonstrate the methodology. Our analysis shows
that binding analysis and constraint exploration are two essential issues in the realization of declarative logic
programming. The limitations of our methodology are also...
197.
Nonmonotonic Inheritance in Object-Oriented Deductive Database Languages
- Wolfgang May,Paul-th. Kandzia
Deductive object-oriented frameworks integrate logic rules and inheritance.
There, specific problems arise: Due to the combination of deduction and
inheritance, (a) deduction can take place depending on inherited facts, thus
raising indirect conflicts, and (b) also the class hierarchy and-membership
is subject to deduction. From this point of view, we investigate the application
of the extension semantics of Default Logic to deductive object-oriented
database languages. By restricting the problem to Horn programs and a
special type of defaults tailored to the semantics of inheritance, a forwardchaining
construction of a Herbrand-style representation of extensions is possible.
This construction is compared with a solution as implemented in the
F-Logic system Florid which...
198.
Autoepistemic Logic of First Order and Its Expressive Power
- Li Yan Yuan
We study the expressive power of first order autoepistemic logic
1
. We argue that full
introspection of rational agents should be carried out by minimizing positive introspection
and maximizing negative introspection. Based on full introspection, we propose the generalized
stable semantics that characterizes autoepistemic reasoning processes of rational
agents, and show that the breadth of the semantics covers all theories in autoepistemic
logic of first order, Moore's AE logic, and Reiter's default logic.
Our study demonstrates that autoepistemic logic of first order is a very powerful framework
for nonmonotonic reasoning, logic programming, deductive databases, and knowledge
representation.
Key Words: nonmonotonic reasoning, autoepistemic logic, default logic,
logic programming, knowledge representation
1 Introduction
An idea...
199.
Explaining Program Execution in Deductive Systems
- Tarun Arora,Raghu Ramakrishnan,William G. Roth,Praveen Seshadri,Divesh Srivastava
this paper, we describe Explain, a menu-driven graphical tool for visualizing fact derivations in a logic
programming/deductive database language. It is designed to operate in conjunction with the CORAL deductive
database system [RSSS93b], and deals specifically with (extended) Horn-clause rules evaluated using bottom-up
techniques. It differs significantly from debugging tools available for Prolog-style languages, which are designed
for a top-down, backtracking evaluation strategy. A major difference between bottom-up and top-down strategies
(used in Prolog-like systems) is that no guarantees are offered with respect to execution order in bottom-up
evaluation, and thus, some non-operational abstraction of the computation must be used in explanations. The
abstraction used in the...
200.
Nonmonotonic Inheritance in Object-Oriented Deductive Database Languages
- Wolfgang May,Paul-th. Kandzia
Deductive object-oriented frameworks integrate logic rules and inheritance.
There, specific problems arise: Due to the combination of deduction and
inheritance, (a) deduction can take place depending on inherited facts, thus
raising indirect conflicts, and (b) also the class hierarchy and-membership
is subject to deduction. From this point of view, we investigate the application
of the extension semantics of Default Logic to deductive object-oriented
database languages. By restricting the problem to Horn programs and a
special type of defaults tailored to the semantics of inheritance, a forwardchaining
construction of extensions is possible. This construction is compared
with a solution as implemented in the F-Logic system Florid which is based
on a...
