1.

Panoramas de intermediación de intereses políticos: movimientos sociales, grupos de interés y partidos a comienzos del siglo XXI
- Kischelt, Herbert
En la primera sección de este artículo esbozamos una lógica general de cómo los actores eligen campos de acción colectiva, invierten en movilización colectiva, y enmarcan sus objetivos. Este análisis muestra la posibilidad de que unos modos muy diferenciados de movilizar e intermediar intereses puedan coexistir en un mismo electorado. En la segunda sección sostenemos que se observa empíricamente una transición en las democracias pos-industriales avanzadas de sistemas de movilizar e intermediar intereses de tipo �fusionado� a otros de tipo �diferenciado�. Estas tendencias no se pueden identificar con un �declive� o una �decadencia� de las democracias contemporáneas, como proponen otros...

2.

Massively parallel Support for Nonmonotonic Reasoning
- B. Boutsinas; Y. C. Stamatiou; G. Pavlides
INTRODUCTION Nonmonotonic reasoning plays an important role in the development of systems that try to mimic commonsense reasoning. Human beings are constantly forced to make decisions and reach conclusions in a fuzzy world. The knowledge that can be acquired by observation is inherently incomplete and may even contain conflicting information as well as exceptions to general rules. Formal logic systems do not seem to provide a satisfactory solution in such an environment (see for example [19,3]) in terms of efficiency. It has been shown, that many of these systems have decision problems that are intractable, or even undecidable, when stated...

3.

Assumption-based modeling using ABEL
- B. Anrig; R. Haenni; J. Kohlas; N. Lehmann
Abstract. Today, different formalisms exist to solve reasoning problems under uncertainty. For most of the known formalisms, corresponding computer implementations are available. The problem is that each of the existing systems has its own user interface and an individual language to model the knowledge and the queries. This paper proposes ABEL, a new and general language to express uncertain knowledge and corresponding queries. Examples from different domains show that ABEL is powerful and general enough to be used as common modeling language for the existing software systems. A prototype of ABEL is implemented in Evidenzia, a system restricted to models...

4.

What is the Normative Role of Logic?
Abstract: The paper tries to spell out a connection between deductive logic and rationality, against Harman’s arguments that there is no such connection, and also against the thought that any such connection would preclude rational change in logic. One might not need to connect logic to rationality if one could view logic as the science of what preserves truth by a certain kind of necessity (or, by necessity plus logical form); but the paper points out a serious obstacle to any such view. What is the connection between (deductive) logic and rationality? Answers to this vary markedly. At one extreme...

5.

ABSTRACT
- Manuel Carro; José F. Morales; Facultad De Informática; Henk L. Muller; G. Puebla
In this paper we study, through a concrete case, the feasibility of using a high-level, general-purpose logic language in the design and implementation of applications targeting wearable computers. The case study is a “sound spatializer” which, given real-time signals for monaural audio and heading, generates stereo sound which appears to come from a position in space. The use of advanced compile-time transformations and optimizations made it possible to execute code written in a clear style without efficiency or architectural concerns on the target device, while meeting strict existing time and memory constraints. The final executable compares favorably with a similar...

6.

A Logic Programming Framework for the Abductive Inference of Intentions in Cooperative Dialogues
- Paulo Quaresma; José Gabriel Lopes
In this paper we propose a general logic programming framework allowing the recognition of plans and intentions behind speech acts through abductive reasoning. These inferences enables each agent to have an active participation in dialogues, namely in cooperative informationseeking dialogues. In our framework the possible actions, events, states and world knowledge are represented by extended logic programs (LP with explicit negation) and the abductive inference process is modeled by a framework wich is based on the Well Founded Semantics augmented with explicit negation (WFSX) and contradiction removal semantics (CRSX) ([13]). It will be shown how this framework supports abductive reasoning...

7.

Stable Models and an Alternative Logic Programming Paradigm
- Victor W. Marek; Mirosaw Truszczynski
Stable model semantics appeared... In this paper we argue that rather than to try to resolve these inconsistencies and force stable model semantics into a standard logic programming mold (this effort most likely is doomed to failure), a change of view is required. Therefore, we propose a perspective on the stable model semantics that departs from several basic tenets of logic programming. At the same time, this perspective leads to a computational system very much in the general spirit of logic programming. The system is declarative...

8.

Directional Type Checking for Logic Programs: Beyond Discriminative Types
- Witold Charatonik
Directional types form a type system for logic programs which is based on the view of a predicate as a directional procedure which, when applied to a tuple of input terms, generates a tuple of output terms. It is known that directional-type checking wrt. arbitrary types is undecidable; several authors proved decidability of the problem wrt. discriminative regular types. In this paper, using techniques based on tree automata, we show that directional-type checking for logic programs wrt. general regular types is DEXPTIME-complete and fixed-parameter linear. The letter result shows that despite the exponential lower bound, the type system might be...

9.

Coding Computations with Stable Models of logic Programs
- Jeffrey B. Remmel
We give several examples of how to code computations of both nondeterministic and deterministic Turing machines as the set of stable models of a general logic program. First we answer of question of Marek and Truszczynski [4] concerning what search problems can be represented as the set of stable of model of Datalog programs with negation. That is, a search problem consists of a set of finite instances, D , such that for each instance I 2 D , there is a nite set S (I) of all solutions of for that instance I, see [3]. We show that all...

10.

Cautious Models for General Logic Programs
- Tomi Janhunen; Fin- Espoo
In this paper, cautious models of general logic programs are investigated. Such models are constructed iteratively using a monotonic operator which performs case analysis on total interpretations generated by enumerations of atoms. Consequently, every general logic program has a unique cautious model. The new class of partial models is compared with well-founded and stable models of general logic programs. Various extensions of these models are are also addressed. The time complexity of constructing cautious models is analyzed. Results indicate that the major reasoning task is co-NP-complete. Finally, the connection to cautious autoepistemic logic is explained. 1 Introduction A deønite logic...

11.

Inductive Synthesis of Recursive Logic Programs: Achievements and Prospects
- Pierre Flener; Serap Yılmaz
The inductive synthesis of recursive logic programs from incomplete information, such as input/output examples, is a challenging subfield both of ILP (Inductive Logic Programming) and of the synthesis (in general) of logic programs from formal specifications. We first overview past and present achievements, focusing on the techniques that were designed specifically for the inductive synthesis of recursive logic programs, but also discussing a few general ILP techniques that can also induce non-recursive hypotheses. Then we analyse the prospects of these techniques in this task, investigating their applicability to software engineering as well as to knowledge acquisition and discovery.

12.

Dynamic Logic Programming with Multiple Dimensions
- João Alexandre Leite; José Júlio Alferes; Luís Moniz Pereira
According to the recently introduced notion of Dynamic Logic Programming, knowledge is given by a set of theories (encoded as logic programs) representing different states of the world. Different states may represent different time periods, different hierarchical instances, or even different domains. The mutual relationships extant between different states are used to determine the semantics of the combined theory composed of all individual theories. Although suitable to encode one of the possible representational dimensions (e.g. time, hierarchies, domains,...), Dynamic Logic Programming cannot deal with more than one such dimensions simultaneously because it is only defined for linear sequences of states....

13.

Dynamic Logic Programming with Multiple Dimensions
- João Alexandre Leite; José Júlio Alferes; Luís Moniz Pereira
According to the recently introduced notion of Dynamic Logic Programming, knowledge is given by a set of theories (encoded as logic programs) representing different states of the world. Different states may represent different time periods, different hierarchical instances, or even different domains. The mutual relationships between different states are used to determine the semantics of the combined theory composed of all individual theories. Although suitable to encode one of the possible representational dimensions (e.g. time, hierarchies, domains,...), Dynamic Logic Programming cannot deal with more than one such dimensions simultaneously because it is only defined for linear sequences of states. In...

14.

Evolving logic programs
- José Júlio Alferes; Antonio Brogi; João Alexandre Leite; Luís Moniz Pereira
Logic programming has often been considered less than adequate for modelling the dynamics of knowledge changing over time. In this paper we describe a simple though quite powerful approach to modelling the updates of knowledge bases expressed by generalized logic programs, by means of a new language, hereby christened EVOLP (after EVOlving Logic Programs). The approach was first sparked by a critical analysis of previous efforts and results in this direction [1, 2, 7, 11], and aims to provide a simpler, and at once more general, formulation of logic program updating, which runs closer to traditional logic programming (LP) doctrine....

15.

Modular Logic Programming
- José Júlio Alferes; Antonio Brogi; João Alexandre Leite; Luís Moniz Pereira
Logic programming has often been considered less than adequate for modelling the dynamics of knowledge changing over time. In this paper we describe a simple though quite powerful approach to modelling the updates of knowledge bases expressed by generalized logic programs, by means of a new language, hereby christened EVOLP (after EVOlving Logic Programs). The approach was first sparked by a critical analysis of previous efforts and results in this direction [1,2,7,11], and aims to provide a simpler, and at once more general, formulation of logic program updating, which runs closer to traditional logic programming (LP) doctrine. From the syntactical...

16.

Inductive Synthesis Of Recursive Logic Programs
- Engineering And Information; Serap Ylmaz; Serap Ylmaz
INDUCTIVE SYNTHESIS OF RECURSIVE LOGIC PROGRAMS Serap Ylmaz M.S. in Computer Engineering and Information Science Supervisor: Ass't Prof. Pierre Flener August 1997 The learning of recursive logic programs (i.e. the class of logic programs where at least one clause is recursive) from incomplete information, such as input/output examples, is a challenging subfield both of ILP (Inductive Logic Programming) and of the synthesis (in general) of logic programs from formal specifications. This is an extremely important class of logic programs, as the recent work on constructive induction shows that necessarily invented predicates have recursive programs, and it even turns out that...

17.

Classical Logic Event Calculus as Answer Set Programming
- Joohyung Lee; Ravi Palla
Abstract. Recently, Ferraris, Lee and Lifschitz presented a generalized definition of a stable model that applies to the syntax of arbitrary firstorder sentences, under which a logic program is viewed as a special class of first-order sentences. The new definition of a stable model is similar to the definition of circumscription, and can even be characterized in terms of circumscription. In this paper, we show the opposite direction, that is, how to embed circumscription into the new stable model semantics, and based on this, how to turn some versions of the classical logic event calculus into the general language of...

18.

Synthesis for testability: Circuits derived from ordered kronecker functional decision diagrams
- Bernd Becker; Rolf Drechsler
Testability properties of circuits derived from Ordered Kronecker Functional Decision Diagrams (OKFDDs) [2] are studied with respect to the Stuck-At Fault Model (SAFM) and the Cellular Fault Model (CFM). The computation of complete test sets and of all occuring redundanciescan be done easily and efciently and circuits with high testability can be obtained. The full paper [1] including experimental results can be obtained from the authors. 1 OKFDD-Circuits In general, a Combinational Logic Circuit (CLC) is de ned over a xed library and modeled as a directed acyclic graph C =(V; E) with some additional properties. Very often a standard...

19.

From possibilistic information to Kleene’s strong multivalued logics
- Gert De Cooman; Vakgroep Elektrische Energietechniek
1 Possibilistic extension logics Possibilistic logic in general [7, 8, 9, 10] investigates how possibilistic uncertainty about propositions is propagated when making inferences in a formal logical system. In this paper, we look at a very particular aspect of possibilistic logic: we investigate how, under certain independence assumptions, the introduction of possibilistic uncertainty in classical propositional logic leads to the consideration of special classes of multi-valued logics, with a proper set of truth values and logical functions combining them. First, we show how possibilistic uncertainty about the truth value of a proposition leads to the introduction of possibilistic truth values....

20.

On the relationship between spatial logics and behavioral simulations. Tech. rep. available at http://rap.dsi.unifi.it/~acciai
- Lucia Acciai; Michele Boreale; Gianluigi Zavattaro
Abstract. Spatial logics have been introduced to reason about distributed computation in models for concurrency. We first define a spatial logic for a general class of infinite-state transition systems, the Spatial Transition Systems (sts), where a monoidal structure on states accounts for the spatial dimension. We then show that the model checking problem for this logic is undecidable already when interpreted over Petri nets. Next, building on work by Finkel and Schnöbelen, we introduce a subclass of sts, the Well-Structured sts (ws-sts), which is general enough to include such models as Petri nets, Broadcast Protocols, ccs and Weighted Automata. Over...