Infinite games with finite knowledge gaps

Infinite games where several players seek to coordinate under imperfect information are deemed to be undecidable, unless the information is hierarchically ordered among the players. We identify a class of games for which joint winning strategies can be constructed effectively without restricting the direction of information flow. Instead, our condition requires that the players attain common knowledge about the actual state of the game over and over again along every play. We show that it is decidable whether a given game satisfies the condition, and prove tight complexity bounds for the strategy synthesis problem under $\omega$-regular winning conditions given by parity automata.Comment: 39 pages; 2nd revision; submitted to Information and Computatio

Changing a semantics: opportunism or courage?

The generalized models for higher-order logics introduced by Leon Henkin, and their multiple offspring over the years, have become a standard tool in many areas of logic. Even so, discussion has persisted about their technical status, and perhaps even their conceptual legitimacy. This paper gives a systematic view of generalized model techniques, discusses what they mean in mathematical and philosophical terms, and presents a few technical themes and results about their role in algebraic representation, calibrating provability, lowering complexity, understanding fixed-point logics, and achieving set-theoretic absoluteness. We also show how thinking about Henkin's approach to semantics of logical systems in this generality can yield new results, dispelling the impression of adhocness. This paper is dedicated to Leon Henkin, a deep logician who has changed the way we all work, while also being an always open, modest, and encouraging colleague and friend.Comment: 27 pages. To appear in: The life and work of Leon Henkin: Essays on his contributions (Studies in Universal Logic) eds: Manzano, M., Sain, I. and Alonso, E., 201

Teaching a foreing language to students with communication and language disorders: an intervention proposal

This paper centers on the teaching of a foreign language to students with communication and language disorders. More specifically, it deals with disorders associated with the communicative field e.g. Selective/Elective mutism; language disorders e.g. Aphasia and Dysphasia; and speech disorders e.g. Dysphonia, Dyslalia, Dysglossia, Dysarthria, and Dysphemia. Therefore, I consider that this work can provide with useful information on how to teach students suffering these disorders. Firstly, as a non-native English speaker, researching on this particular area will help me in the sense that it will give me more knowledge about the teaching of English Grammar in general terms and about the disorders at stake. Secondly, as an early-stage researcher, I will become familiar with the procedure of reviewing scientific literature, collecting data, interpreting results and designing my own intervention proposal. Moreover, it has provided me with the opportunity to undertake research on topic of Attention to diversity, specifically on the communication and language disorders. I have selected this field given that researchers have worked on the topics of teaching English grammar, or Attention to diversity, or communication and language disorders. Nonetheless, I have found an information gap on how to teach a second language to students suffering language impairments.Departamento de Didáctica de la Lengua y LiteraturaMáster en Profesor de Educación Secundaria Obligatoria y Bachillerato, Formación Profesional y Enseñanzas de Idioma

An investigation into the effect of a novel non-linguistic cognitive intervention on functional communication in global aphasia

Background: Global aphasia is a severe communication disorder affecting all language modalities, commonly caused by stroke. Evidence as to whether the functional communication of people with global aphasia (PwGA) can improve after speech and language therapy is limited and conflicting. This is partly because cognition is essential for successful functional communication and in global aphasia it can be severely impaired. Cognitive treatments aimed at improving functional communication in people with aphasia exist, but few have been trialled with PwGA and none have robustly demonstrated gains. This study explored the effect of a novel cognitive intervention on the functional communication skills of PwGA. Method: A survey investigated the practices, challenges and research priorities of UK based speech and language therapists. Intervention for PwGA was found to commonly target choice-making or non-verbal communication. However, co-occurring cognitive difficulties were reported to limit progress and present a challenge when engaging clients. Synthesising these findings with a review of the literature, a non-linguistic intervention targeting the cognitive skills underpinning functional communication was developed and delivered to six participants (recruited from NHS and independent neurorehabilitation services), three times weekly for up to 6 weeks. A multiple baseline case series design investigated changes in functional communication (as measured by a proxy rating of communication independence and quality, and a new scenario-based observational tool), cognition and auditory comprehension. Results: Participants completed this novel intervention programme in an average of nine sessions. Five out of six participants made significant gains in functional communication as measured by a proxy, and non-verbal semantics. Auditory comprehension also significantly improved in two individuals. Conclusion: There is preliminary evidence that this intervention can improve functional communication in some PwGA. Findings add to the evidence that cognition is critical to functional communication and highlight the benefit of treating cognition via non- linguistic means in PwGA

On the Right Path: A Modal Logic for Supervised Learning

Formal learning theory formalizes the process of inferring a general result from examples, as in the case of inferring grammars from sentences when learning a language. Although empirical evidence suggests that children can learn a language without responding to the correction of linguistic mistakes, the importance of Teacher in many other paradigms is significant. Instead of focusing only on learner(s), this work develops a general framework---the supervised learning game (SLG)---to investigate the interaction between Teacher and Learner. In particular, our proposal highlights several interesting features of the agents: on the one hand,Learner may make mistakes in the learning process, and she may also ignore the potential relation between different hypotheses; on the other hand, Teacher is able to correct Learner's mistakes, eliminate potential mistakes and point out the facts ignored by Learner. To reason about strategies in this game, we develop a modal logic of supervised learning (SLL). Broadly, this work takes a small step towards studying the interaction between graph games, logics and formal learning theory.Comment: The paper was accepted by LORI 2019. But due to the page-limit constraints, that Proceedings version does not include any proofs. In this version, we show the proofs for the result

Communication in concurrent dynamic logic

AbstractCommunication mechanisms are introduced into the program schemes of Concurrent Dynamic Logic, on both the propositional and the first-order levels. The effects of these mechanisms (particularly, channels, shared variables, and “message collectors”) on issues of expressiveness and decidability are investigated. In general, we find that both respects are dominated by the extent to which the capabilities of synchronization and (unbounded counting are enabled in the communication scheme

The Spanish Gitanos of Mexico City: Rhythmicity, Mimesis and Domestication of the Payos

This text addresses a tentative approach to groups in Mexico such as the Roma, who remain poorly known. The analysis focuses on problematizing the particular cultural and economic reproduction strategies of an urban group of Gitanos (Calós) in Mexico City. Greater attention is placed particularly onthe performance and the mimesis in economic exchange with the Payos (non-Gitanos). The idea is that the processes of cultural identification refer to the basic Caló social universe, which reveals epistemological beliefs and assumptions shared by the group in relation to the Payo universe. The idea is that the Calós construct idealized models of the real world during everyday experience in the ecological context within the community. Instead, it relates to the direct perceptual involvement of subjects in a relational context of shared patterns of daily activities in environments that are experienced. The effect is the domestication of the Payo’s world

Meaning Negotiation

While "meaning negotiation" has become an ubiquitous term, its use is often confusing. A negotiation problem implies not only a convenience to agree, but also diverging interest on what to agree upon. It implies agreement but also the possibility of (voluntary) disagreement. In this chapter, we look at meaning negotiation as the process through which agents starting from different preferred conceptual representations of an object, an event or a more complex entity, converge to an agreement through some communication medium. We shortly sketch the outline of a geometric view of meaning negotiation, based on conceptual spaces. We show that such view can inherit important structural elements from game theoretic models of bargaining – in particular, in the case when the protagonists have overlapping negotiation regions, we emphasize a parallel to the Nash solution in cooperative game theory. When acceptable solution regions of the protagonists are disjoint, we present several types of processes: changes in the salience of dimensions, dimensional projections and metaphorical space transformations. None of the latter processes are motivated by normative or rationality considerations, but presented as argumentation tools that we believe are used in actual situations of conceptual disagreement

A Modal Logic for Supervised Learning

Formal learning theory formalizes the process of inferring a general result from examples, as in the case of inferring grammars from sentences when learning a language. In this work, we develop a general framework—the supervised learning game—to investigate the interaction between Teacher and Learner. In particular, our proposal highlights several interesting features of the agents: on the one hand, Learner may make mistakes in the learning process, and she may also ignore the potential relation between different hypotheses; on the other hand, Teacher is able to correct Learner’s mistakes, eliminate potential mistakes and point out the facts ignored by Learner. To reason about strategies in this game, we develop a modal logic of supervised learning and study its properties. Broadly, this work takes a small step towards studying the interaction between graph games, logics and formal learning theory.acceptedVersio