Simposio de Lingüística, Lógica y Computación (1-2-2010)

Fecha: 1-02-2010.

Hora: 10:30 h.

Lugar: Hotel AC Málaga Palacio.

Más información: https://sevein.matap.uma.es/~aciego/lLI-2010/Bienvenida.html.

Introducción: En mayo de 2007 se celebró un primer Simposio de Lingüística, Lógica y Computación, organizado por el Grupo de Investigación de Matemática Aplicada en Computación (GIMAC: https://www.gimac.uma.es) en la Universidad de Málaga.  De nuevo en 2010, volvemos a organizar una nueva edición con la incorporación de destacados investigadores procedentes de prestigiosas Universidades extranjeras.

El objetivo principal es posibilitar el intercambio de conocimientos y dar a conocer los últimos avances obtenidos en el campo de las interacciones entre lingüística, lógica y computación, así como explorar vías de colaboración entre grupos afines.

Ponentes: Hans van Ditmarsch, Ángel Nepomuceno, Fernando Velázquez y Fernando Soler, Pablo Seban, Emilio Muñoz, N. Madrid, D. Pearce.

“Security protocols using card deals” - Hans van Ditmarsch (Sevilla)
In the mid-19th century, Thomas Kirkman and Jacob Steiner gave birth to what later became known as design theory, a subdiscipline of combinatorial mathematics. Tools and techniques from that area can be used to design unconditionally secure (communicative) protocols. The epistemic logician can also focus on the epistemic properties of such protocols, or reformulate their specifications (such as security requirements) in such terms. Individual, common and distributed knowledge all play a role. Following original contributions from the 1980s onward by Winkler, Fischer, Wright and others, we focus on the case of computationally unlimited agents using card deals. Given various agents or players, two among them (sender and receiver, say, but note that they both send and receive) may wish to communicate a secret. We present some results for the restricted case where secrets concern card ownership, and for the general case where any secret bit can be exchanged by means of such card deals.

“Cálculos deductivos para abducción” - Ángel Nepomuceno (Sevilla)
Se estudiarán las condiciones en que se pueden usar cálculos deductivos para la búsqueda de soluciones a problemas abductivos en contextos inferenciales de estilo clásico. Cada contexto inferencial es representable por una lógica, siendo el estilo clásico característico porque su relación de consecuencia lógica verifica ciertas reglas estructurales. En primera instancia, los cálculos correctos y completos son buenos candidatos para su uso en la búsqueda de soluciones a problemas abductivos, pero ello excluiría los cálculos no completos, como, por ejemplo, los de lógica de segundo orden (con semántica estándar) y los de lógicas con semántica finitaria. Debilitando la exigencia de completud, se establecen las condiciones para la definibilidad de cálculos abductivos sensibles al contexto.

“Un enfoque epistémico-dinámico a la abducción” - Fernando Velázquez (Amsterdam), Fernando Soler (Sevilla)
Proponemos un acercamiento al razonamiento abductivo en lógica epistémica dinámica siguiendo la distinción entre conocimiento implícito y explícito. Podemos concebir la abducción bien como una forma de hacer explícito el conocimiento implícito o bien, siguiendo la noción más tradicional, como la búsqueda de hipótesis que, si fueran explícitamente conocidas por el agente, sería posible transformar la observación en conocimiento explícito. Mostramos las acciones epistémicas necesarias para modelar el razonamiento abductivo.

“It is permitted to say ... “ - Pablo Seban (IRIT Toulouse)
This talk will present a recent work made with Philippe Balbiani and Hans van Ditmarsch. Our goal is to formalize what "having the permission to say" means.  We adapt the dynamic logic of permission considered by van der Meyden in the particular case where atomic actions are public and truthful announcements. Hence, we extend the logic of public announcements by introducing an operator of permission. The models we obtain express situations in which there are restrictions (deontic, rules of a game,...) on announcements.

I will present the syntax and the semantics of our logic, focusing on the problems we had to face (completeness, wanted validities), but also further works on deontic concepts or extensions to other kind of announcements. I'll base the talk on an example of a french card game (« la belote »).

“A New Decision Procedure for Modal Logic K” - Emilio Muñoz (Málaga)
We present a new deduction system for the minimal decidable modal logic K. The system is based on relational dual tableaux. We prove its soundness and completeness and we show that the system itself is a decision procedure. The main advantages of the new approach are: 1) the system is deterministic, that is it generates one tree for a given formula, 2) the system is a validity-checker, hence it generates a proof of a formula (if such exists), 3) the language of deduction and the language of the logic coincide.

“Sobre el concepto de coherencia en programas lógicos residuados” - N. Madrid (Málaga)
En la charla se recordará la noción de coherencia, que fue introducida  en el contexto del Fuzzy Answer Set Programming y se discutirán varias motivaciones para ser considerada como una buena generalización de la inconsistencia en el ambiente difuso. Finalmente se proporcionarán herramientas para medir cuán incoherente es un programa lógico residuado.

“Towards Modular Combinations of Ontologies and Rules” - D. Pearce (UPM)
A growing field of research in knowledge technologies concerns the ways and means of amalgamating description logics and nonmonotonic logic programs in order to combine rule-based reasoning with ontologies. Among the most popular semantics for such hybrid theories are those based on answer set programming (ASP). If hybrid systems are to become a successful, practical tool in knowledge-based reasoning, it seems important to address issues of modularity and robust logical relations between theories - topics that are already being studied in description logics and in ASP separately. In this talk I will look at two kinds of hybrid theories: dl-programs and so-called hybrid knowledge bases (also known as dl + log), with two aims in mind. First, I will try to show how the usual interpretations for these kinds of theories can be re-expressed in a manner much closer to ordinary logical semantics. This means that the hybrid entities become more homogenous and more susceptible to logical analysis. This brings us naturally to my second aim which is to initiate the study of robust  relations of equivalence between hybrid theories. Here it turns out that we can make use of some of the concepts already investigated in answer set programming and description logics - concepts such as equivalence model and query inseparability.