Separating the basic logics of the basic recurrences

This paper shows that, even at the most basic level, the parallel, countable branching and uncountable branching recurrences of Computability Logic (see http://www.cis.upenn.edu/~giorgi/cl.html) validate different principles

The taming of recurrences in computability logic through cirquent calculus, Part I

This paper constructs a cirquent calculus system and proves its soundness and completeness with respect to the semantics of computability logic (see http://www.cis.upenn.edu/~giorgi/cl.html). The logical vocabulary of the system consists of negation, parallel conjunction, parallel disjunction, branching recurrence, and branching corecurrence. The article is published in two parts, with (the present) Part I containing preliminaries and a soundness proof, and (the forthcoming) Part II containing a completeness proof

Temporal hints in the cultural heritage discourse: what can an ontology of time as it is worded reveal?

International audienceTime is an indispensable component of cultural heritage (CH) information: implementing appropriate knowledge models carry crucial importance in order to provide deeper understanding of heritage elements' evolution, to uncover concurrences, and to weigh quality factors. It is a challenging task though due to the uncertain characteristics of temporal data, and to the wording of time in the CH discourse. Existing KR models are either not designed for these distinctive characteristics, or spatial aspects tend to upstage the temporal dimension.This research aims at deciphering and proposing a formal representation of the way temporal hints are formalized in historical narratives. An OWL temporal ontology is introduced that provides a core support mechanism allowing for a semantic representation of temporal statements, and for structural analysis. The objective is to facilitate the cross-examination of temporal hints in and across CH collections so that specialists can have extensive reading possibilities of heritage information.Dans le champ des sciences patrimoniales, la dimension temporelle de l’information joue un rôle à l’évidence majeur tant pour l’interpréter et l’analyser que pour relier des faits isolés. Mais la façon dont cette dimension est verbalisée pose des problèmes de formalisation non triviaux. Pourtant, cette verbalisation, que l’on associe souvent au terme-chapeau d’incertitude, peut être lue en dissociant d’une part le caractère «mal connu» d’un fait doc-umenté, irréductible, et les choix faits par le producteur de l’information pour la «relativiser».Dans cette contribution nous proposons un modèle formel permettant d’observer et d’analyser de façon systématique cette couche de verbalisation. L’expérience est menée sur des données fortement hétérogènes, souvent d’origine citoyenne, documentant le petit pat-rimoine matériel et immatériel. Ce cas d’étude est donc limité, mais il apparait néanmoins comme portant une question de fond allant au-delà du cas d’espèce.La contribution détaille d’abord la grille d’analyse d’indices temporels proposée, puis relate l’expérimentation concrète associée (ontologie OWL). Il n’est pas fait état d’une quelconque prétention à un résultat généralisable stricto sensu, mais cette expérience peut contribuer à nourrir de façon pragmatique un débat nécessaire sur la formalisation d’indices temporels dans les sciences historiques

Sequential operators in computability logic

Computability logic (CL) (see http://www.cis.upenn.edu/~giorgi/cl.html) is a semantical platform and research program for redeveloping logic as a formal theory of computability, as opposed to the formal theory of truth which it has more traditionally been. Formulas in CL stand for (interactive) computational problems, understood as games between a machine and its environment; logical operators represent operations on such entities; and "truth" is understood as existence of an effective solution, i.e., of an algorithmic winning strategy. The formalism of CL is open-ended, and may undergo series of extensions as the study of the subject advances. The main groups of operators on which CL has been focused so far are the parallel, choice, branching, and blind operators. The present paper introduces a new important group of operators, called sequential. The latter come in the form of sequential conjunction and disjunction, sequential quantifiers, and sequential recurrences. As the name may suggest, the algorithmic intuitions associated with this group are those of sequential computations, as opposed to the intuitions of parallel computations associated with the parallel group of operations: playing a sequential combination of games means playing its components in a sequential fashion, one after one. The main technical result of the present paper is a sound and complete axiomatization of the propositional fragment of computability logic whose vocabulary, together with negation, includes all three -- parallel, choice and sequential -- sorts of conjunction and disjunction. An extension of this result to the first-order level is also outlined.Comment: To appear in "Information and Computation

Programming Languages and Systems

This open access book constitutes the proceedings of the 30th European Symposium on Programming, ESOP 2021, which was held during March 27 until April 1, 2021, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2021. The conference was planned to take place in Luxembourg and changed to an online format due to the COVID-19 pandemic. The 24 papers included in this volume were carefully reviewed and selected from 79 submissions. They deal with fundamental issues in the specification, design, analysis, and implementation of programming languages and systems

Are we allowed to use fictional vignettes in cultural geographies?

Fictional vignettes are narrative texts that academic researchers may invent in order to illustrate arguments or to present their research outcomes; they are stories or situations that do not strictly report factual realities observed by the author, but that, in any case, implement the heuristics for the arguments that the author wants to raise. Although there are several works in social sciences taking advantage of fictional narratives, geographers have started mobilising invented stories in their writings mostly recently, provided that a variety of creative methodologies had been introduced. The aim of this article is to present fictional vignettes as an integrative research method and writing technique, while discussing potential opportunities and limits relating to their use in geographical research, particularly within the recent rise of various ‘creative methodologies’ in cultural geographies