— Itis proved that thefamily of finite index matrix languages coincides with the families of finite index random context languages generated withforbidding sets and with or without X-rules and is included in thefamily of finite index conditional languages. Finally, the Szilard languages associated to finite index matrix grammars are briefly investigated. Résumé. — On montre que lafamille de lan...

We present an overview of three approaches to formal meta-theory: the formal study of properties of deductive systems. The approaches studied are: nameless dummy variables (also called de Bruijn indices) dB72], rst order abstract syntax for terms with higher order abstract syntax for judgements MP93, MP97], and higher order abstract syntax Pfe91].

Résumé. Dans cet article, nous introduisons une nouvelle mesure pour qualifier “l’outlier-ness“ de chaque groupe/cluster. Cette mesure, nommée GOF, est intégrée et estimée dans un processus d’apprentissage non supervisé en utilisant les cartes topologiques. Ceci permet d’apprendre la structure des données tout en fournissant un nouveau score (GOF). Ce paramètre est basé sur la densité et quanti...

Many representations of term syntax with variable bindings have been used to formalize programming language metatheory, but so far there is no clear consensus on which is the best representation. We have undertaken an exhaustive comparison between concrete representations, among which are: names, nominal, de Bruijn indices, de Bruijn levels, locally nameless, and their variations. In the contex...

Calculi of explicit substitutions have almost always been presented using de Bruijn indices with the aim of avoiding α-conversion and being as close to machines as possible. De Bruijn indices however, though very suitable for the machine, are difficult to human users. This is the reason for a renewed interest in systems of explicit substitutions using variable names. We believe that the study o...

Résumé. Le volume d’information contenu dans un entrepôt de données s’accroît sans cesse, augmentant de ce fait le temps d’exécution des requêtes décisionnelles. Pour y remédier, l’administrateur doit, durant la phase de conception physique de l’entrepôt, effectuer une sélection de structures d’optimisation (index, vues matérialisées ou fragmentation), puis assurer leur gestion et maintenance. ...