Cut Elimination for a Logic with Induction and Co-induction

Proof search has been used to specify a wide range of computation systems. In order to build a framework for reasoning about such specifications, we make use of a sequent calculus involving induction and co-induction. These proof principles are based on a proof theoretic (rather than set-theoretic) notion of definition. Definitions are akin to logic programs, where the left and right rules for defined atoms allow one to view theories as "closed" or defining fixed points. The use of definitions and free equality makes it possible to reason intentionally about syntax. We add in a consistent way rules for pre and post fixed points, thus allowing the user to reason inductively and co-inductively about properties of computational system making full use of higher-order abstract syntax. Consistency is guaranteed via cut-elimination, where we give the first, to our knowledge, cut-elimination procedure in the presence of general inductive and co-inductive definitions.Comment: 42 pages, submitted to the Journal of Applied Logi

A Labelled Sequent Calculus for BBI: Proof Theory and Proof Search

We present a labelled sequent calculus for Boolean BI, a classical variant of O'Hearn and Pym's logic of Bunched Implication. The calculus is simple, sound, complete, and enjoys cut-elimination. We show that all the structural rules in our proof system, including those rules that manipulate labels, can be localised around applications of certain logical rules, thereby localising the handling of these rules in proof search. Based on this, we demonstrate a free variable calculus that deals with the structural rules lazily in a constraint system. A heuristic method to solve the constraints is proposed in the end, with some experimental results

Fast-food advertising in social media. A case study on Facebook in Egypt

The purpose of this paper is to explore the factors that affect young Egyptian consumers' attitudes towards fast-food advertising in Facebook which is considered the most widely used social media network. 4 focus groups were conducted with young consumers from 2 Egyptian cities. Content analysis was applied for the Egyptian fast-food Facebook fan pages with the aid of the NVivo software. The findings of this exploratory study have shown that young consumers are accepting the idea of fast food advertising in Facebook. Moreover, the research provides a framework for the factors that lead to consumers' engagement with the advertisements on Facebook. With the increase in the popularity of social media websites among the young generation, fast-food marketers find it a more effective medium for advertising for their chains among that segment. The research provides insights for marketers to make their advertisements more effective on Facebook. The participants in the focus groups were young consumers in Egypt. It would be useful to expand the sample and conduct the research in other developing and developed countries with more consumers from other age groups. Consumer attitude towards advertising as a topic generates interest from academics and practitioners in looking at analysis of the effectiveness and success of advertisements in social media. Therefore this research adds value in that, so far, there is very little academic literature on this particular topic examining young Egyptian consumers' attitudes towards fast-food advertising in Facebook

Liberating the modern Chinese football fan: a theoretical perspective

The cultural and philosophical heritage of modernism underpinning general marketing management theory imparts profound implications for organisations operating in professional sport. This theoretical paper uses the context of China’s professional football industry to argue that marketing may benefit from a more postmodern approach to marketing management

Myopia, customer returns and the theory of planned behaviour

As a prevalent and growing form of customer behaviour, deshopping is on the rise. Retailers' focus on good customer service and the offering of lenient returns polices has led to the growth in this fraudulent behaviour of customers in returning goods. This paper considers retailer myopia in the context of dishonest customer returns, applying the Theory of Planned Behaviour (TPB) using a quantitative questionnaire with 535 female consumers. The findings highlight the extent of the behaviour with 50% admitting to partaking in deshopping. The TPB variables can be utilised to manage and prevent deshopping. The results indicate that currently these customers perceive it to be easy to deshop as there are no consequences with the result that such behaviour continues to grow. If retailers were less myopic they would monitor returns more thoroughly and make it less easy for such customers to get away with undesirable deshopping behaviour. The paper makes recommendations for retailers to manage or alter perceived behavioural characteristics for customers, which in turn, would reduce tendencies for dishonesty in customers returning goods for refunds. Retail myopia is evident with deshopping behaviour with consequences for retailers in time, effort and costs