Discovering Classes of Strongly Equivalent Logic Programs

In this paper we apply computer-aided theorem discovery technique to discover theorems about strongly equivalent logic programs under the answer set semantics. Our discovered theorems capture new classes of strongly equivalent logic programs that can lead to new program simplification rules that preserve strong equivalence. Specifically, with the help of computers, we discovered exact conditions that capture the strong equivalence between a rule and the empty set, between two rules, between two rules and one of the two rules, between two rules and another rule, and between three rules and two of the three rules

Becoming an Agile Warrior - An Examination of using a Constructivist Approach to Learning During Basic Training in the British Army.

The British Army has been on the receiving end of Government cuts to numbers of full-time (regular) service personnel following the 2010 Strategic Defence and Security Review and proposed 2018 National Security Review. With numbers being reduced from 102,000 to 82,000, there could be a potential further reduction to 70,000 regular personnel, equivalent to two-thirds of the French Army. The challenge the British Army faces is maximising the performance of the organisation and the individuals who serve in it. As a result, the Agile Warrior concept was developed to promote thinking skills throughout all ranks. This was facilitated by the introduction of a constructivist approach, underpinning the way learning is conducted from a behaviourist, instructor-led style to a student-centred approach to learning. This method was to be trialled at Phase 1 training establishments. This EdD thesis sought to both unpack the current understanding of the complexities of Phase 1 training including its design and implementation, and evaluate a potential solution in linking the design, instructors, recruits and organisational aims of the British Army. In order to achieve this, the thesis was divided into two studies focussing on the training design and instructional methodologies respectively. Study 1 of this thesis initially sought to examine the training design for Phase 1 training delivered at the Army Training Centre (ATC) based in Pirbright. Interviews were conducted with staff members involved in the training design of Phase 1 and recruits in order to gauge the different sides. What emerged from the results was a friction between the standardisation of training design and the instructors want for flexibility to teach in ways they saw appropriate. This finding indicated a gap that could potentially be filled by employing the Present, Apply, Review (PAR) method as the constructivist vehicle for instructors. Study 2 sought to analyse the impact of PAR in bridging the gap between the standardised requirements of Phase 1 whilst providing flexibility for instructors to teach. A mixed method, quasi-experimental design was used for data collection in order to analyse the thoughts of 239 recruits during their Phase 1 training. The findings of a pre-post survey found no difference in regard to the impact of PAR compared with non-PAR instruction using motivation, self-regulated learning and reflection as measurable constructs. Follow-up semi-structured interviews were conducted with ten recruits in order to further unpack the findings. Overall, this research unpacked recruit experiences of Phase 1 training. The findings suggested that factors such as the impact of the instructor, time as a restrictive factor, and the motivational climate facilitated by Phase 1 training had a potentially overriding impact over the specific instructional method delivered by the instructors. It is suggested that the constructivist approach be employed in unit training within the wider army and that further studies should examine its impact within that context

Temporal Answer Set Programming

[Abstract] Commonsense temporal reasoning is full of situations that require drawing default conclusions, since we rarely have all the information available. Unfortunately, most modal temporal logics cannot accommodate default reasoning, since they typically deal with a monotonic inference relation. On the other hand, non-monotonic approaches are very expensive and their treatment of time is not so well delimited and studied as in modal logic. Temporal Equilibrium Logic (TEL) is the first non-monotonic temporal logic which fully covers the syntax of some standard modal temporal approach without requiring further constructions. TEL shares the syntax of Linear-time Temporal Logic (LTL) (first proposed by Arthur Prior and later extended by Hans Kamp) which has become one of the simplest, most used and best known temporal logics in Theoretical Computer Science. Although TEL had been already defined, few results were known about its fundamental properties and nothing at all on potential computational methods that could be applied for practical purposes. This situation unfavourably contrasted with the huge body of knowledge available for LTL, both in well-known formal properties and in computing methods with practical implementations. In this thesis we have mostly filled this gap, following a research program that has systematically analysed different essential properties of TEL and, simultaneously, built computational tools for its practical application. As an overall, this thesis collects a corpus of results that constitutes a significant breakthrough in the knowledge about TEL.[Resumen] El razonamiento temporal del sentido común está lleno de situaciones que requieren suponer conclusiones por defecto, puesto que raramente contamos con toda la información disponible. Lamentablemente, la mayoría de lógicas modales temporales no permiten modelar este tipo de razonamiento por defecto debido a que, típicamente, se definen por medio de relaciones de inferencia monótonas. Por el contrario, las aproximaciones no monótonas existentes son típicamente muy costosas pero su manejo del tiempo no está tan bien delimitado como en lógica modal. Temporal Equilibrium Logic (TEL) es la primera lógica temporal no monótona que cubre totalmente la sintaxis de alguna de las lógicas modales tradicionales sin requerir el uso de más construcciones. TEL comparte la sintaxis de Linear-time Temporal Logic (LTL) (formalismo propuesto por Arthur Prior y posteriormente extendido por Hans Kamp), que es una de las lógicas más simples, utilizadas y mejor conocidas en Teoría de la Computación. Aunque TEL había sido definido, muy pocas propiedades eran conocidas, lo que contrastaba con el vasto conocimiento de LTL que está presente en el estado del arte. En esta tesis hemos estudiado diferentes aspectos de TEL, una novedosa combinación de lógica modal temporal y un formalismo no monótono. A grandes rasgos, esta tesis recoge un conjunto de resultados, tanto desde el punto de vista teórico como práctico, que constituye un gran avance en lo relativo al conocimiento sobre TEL.[Resumo] O razoamento do sentido común aplicado ao caso temporal está cheo de situacións que requiren supoñer conclusións por defecto, posto que raramente contamos con toda a información dispoñible. Lamentablemente a maioría de lóxicas modais temporáis non permiten modelar este tipo de razoamento por defecto debido a que, típicamente, están definidas por medio de relacións de inferencia monótonas. Pola contra, as aproximacións non monótonas existentes son moi costosos e o seu tratamento do tempo non está ben tan delimitado nin estudiado como nas lóxicas modais. Temporal Equilibrium Logic (TEL) é a primeira aproximación non monótona que cubre totalmente a sintaxe dalgunha das lóxicas modais traidicionáis sen requerir o uso de máis construccións. TEL comparte a sintaxe de Lineartime Temporal Logic (LTL) (formalismo proposto por Arthur Prior e extendido posteriormente por Hans Kamp), que é considerada unha das lóxicas modais máis simples, utilizadas e coñecidas dentro da Teoría da Computación. Aínda que TEL xa fora definido previamente, moi poucas das súas propiedades eran coñecidas, dato que contrasta co vasto coñecemento de LTL existente no estado da arte. Nesta tese, estudiamos diferentes aspectos de TEL, unha novidosa combinación de lóxica modal temporal e un formalimo non monótono. A grandes rasgos, esta tese recolle un conxunto de resultados, tanto dende o punto de vista teórico como práctico, que constitúe un gran avance no relativo ó coñecemento sobre o formalismo TEL

Proceedings of the 11th Workshop on Nonmonotonic Reasoning

These are the proceedings of the 11th Nonmonotonic Reasoning Workshop. The aim of this series is to bring together active researchers in the broad area of nonmonotonic reasoning, including belief revision, reasoning about actions, planning, logic programming, argumentation, causality, probabilistic and possibilistic approaches to KR, and other related topics. As part of the program of the 11th workshop, we have assessed the status of the field and discussed issues such as: Significant recent achievements in the theory and automation of NMR; Critical short and long term goals for NMR; Emerging new research directions in NMR; Practical applications of NMR; Significance of NMR to knowledge representation and AI in general

Beyond Logic. Proceedings of the Conference held in Cerisy-la-Salle, 22-27 May 2017

The project "Beyond Logic" is devoted to what hypothetical reasoning is all about when we go beyond the realm of "pure" logic into the world where logic is applied. As such extralogical areas we have chosen philosophy of science as an application within philosophy, informatics as an application within the formal sciences, and law as an application within the field of social interaction. The aim of the conference was to allow philosophers, logicians and computer scientists to present their work in connection with these three areas. The conference took place 22-27 May, 2017 in Cerisy-la-Salle at the Centre Culturel International de Cerisy. The proceedings collect abstracts, slides and papers of the presentations given, as well as a contribution from a speaker who was unable to attend