Type Inference for Records in a Natural Extension of ML

We describe an extension of ML with records where inheritance is given by ML generic polymorphism. All operations on records introduced by Wand in [Wan87] are supported, in particular the unrestricted extension of a field, and other operations such as renaming of fields are added. The solution relies on both an extension of ML, where the language of types is sorted and considered modulo equations [Rem9Ob], and on a record extension of types [Rem9Oc]. The solution is simple and modular and the type inference algorithm is efficient in practice

Description de Marcusenius meronai, espèce nouvelle de Mormyridae (Teleostei) de Sierra Leone

#Marcusenius meronai est décrit du Bagbé et du Rokel en Sierra Leone. Un tableau comparatif des principaux caractères métriques et méristiques des #Marcusenius d'Afrique de l'Ouest est donné ainsi qu'une clé de détermination pour les neuf espèces de cette zone géographique. (Résumé d'auteur

Extension of ML type system with a sorted equation theory on types

Projet FORMELWe extend the ML language by alowing a sorted regular equational theory on types for which unification is decidable and unitary. We prove that the extension keeps principal typings and subject reduction. A new set of typing rules is proposed so that type generalization is simpler and more efficient. We consider typing problems as general unification problems, which we solve with a formalism of unificands. Unificands naturally deal with sharing between types and lead to a more efficient type inference algorithm by splitting it into more elementary steps

Metabolomic Insights into Marine Phytoplankton Diversity

International audienceThe democratization of sequencing technologies fostered a leap in our knowledge of the diversity of marine phytoplanktonic microalgae, revealing many previously unknown species and lineages. The evolutionary history of the diversification of microalgae can be inferred from the analysis of their genome sequences. However, the link between the DNA sequence and the associated phenotype is notoriously difficult to assess, all the more so for marine phytoplanktonic microalgae for which the lab culture and, thus, biological experimentation is very tedious. Here, we explore the potential of a high-throughput untargeted metabolomic approach to explore the phenotypic-genotypic gap in 12 marine microalgae encompassing 1.2 billion years of evolution. We identified species-and lineage-specific metabolites. We also provide evidence of a very good correlation between the molecular divergence, inferred from the DNA sequences, and the metabolomic divergence, inferred from the complete metabolomic profiles. These results provide novel insights into the potential of chemotaxonomy in marine phytoplankton and support the hypothesis of a metabolomic clock, suggesting that DNA and metabolomic profiles co-evolve

An Oriented Convergent Mutation Operator for Solving a Scalable Convergent Demand Responsive Transport Problem

International audienceThis paper presents a method for solving the convergence demand responsive transport problem, by using a stochastic approach based on a steady state genetic algorithm for enumerating a set of optimizing sprawling spanning trees, which constitute the best solutions to this problem. Specifically designed to speed up the convergence to optimal solutions, we introduce an oriented convergent mutation operator, allowing multi-objective considerations. So this solution lays the first stakes for considering real-time solving of such a problem. Led by computer science and geography laboratories, this study is provided with a set of experimental results evaluating the approach

Comparison of three algorithms for solving the convergent demand responsive transportation problem

International audienceLed by computer science and geography laboratories, this paper presents three algorithms for solving the Convergent Demand Responsive Transport Problem (CDRTP). Two of them are exact: the first one is based on a dynamic programming algorithm to enumerate exhaustively the sprawling spanning trees and the second one is based on a depth first search algorithm. The third one is stochastic and uses a steady state genetic algorithm. These approaches address the problems of scalability and flexibility, are compared and discussed

Instability results related to compresible Korteweg system

International audienceThis paper presents the study of surface tension effects in compressible mixtures in the framework of diffuse interface models. In the first part, we describe results previously obtained on the so--called compressible Korteweg and shallow water models and we present nonlinear stability using energy estimates and a new entropy equality recently discovered. These diffuse interface models also allow to take account of capillarity effects in turbulent mixtures and plasma flows subject to Rayleigh-Taylor instabilities. The aim of the last part is to study the influence of surface tension on this instability phenomena

Ambivalent Types for Principal Type Inference with GADTs (extended version)

GADTs, short for Generalized Algebraic DataTypes, which allow constructors of algebraic datatypes to be non-surjective, have many useful applications. However, pattern matching on GADTsintroduces local type equality assumptions, which are a source of ambiguities that may destroy principal types---and must be resolved by type annotations. We introduce ambivalent types to tighten the definition of ambiguities and better confine them, so that type inference has principal types, remains monotonic, and requires fewer type annotations

Simple, partial type-inference for System F based on type-containment

We explore partial type-inference for System F based on type-containment. We consider both cases of a purely functional semantics and a call-by-value stateful semantics. To enable type-inference, we require higher-rank polymorphism to be user-specified via type annotations on source terms. We allow implicit predicative type-containment and explicit impredicative type-instantiation. We obtain a core language that is both as expressive as System F and conservative over ML. Its type system has a simple logical specification and a partial type-reconstruction algorithm that are both very close to the ones for ML. We then propose a surface language where some annotations may be omitted and rebuilt by some algorithmically defined but logically incomplete elaboration mechanism

Freshwater fishes of Sierra Leone and Liberia : annotated checklist and distribution

A partir des collections déposées dans les muséums d'histoire naturelle européens et dans un muséum américain, réalisées en partie par les auteurs et à partir de travaux effectués dans cette zone, une mise à jour des connaissances de la faune ichtyologique des bassins côtiers de la Sierra Leone et du Liberia est présentée. Il a été tenu compte pour la nomenclature des révisions les plus récentes. Des listes par bassin hydrographique ont été établies qui doivent servir de base à un travail d'ensemble sur la zoogéograhie des poissons d'Afrique de l'ouest. (Résumé d'auteur