Layered and Object-Based Game Semantics *

International audienceLarge-scale software verification relies critically on the use of compositional languages, semantic models, specifications, and verification techniques. Recent work on certified abstraction layers synthesizes game semantics, the refinement calculus, and algebraic effects to enable the composition of heterogeneous components into larger certified systems. However, in existing models of certified abstraction layers, compositionality is restricted by the lack of encapsulation of state. In this paper, we present a novel game model for certified abstraction layers where the semantics of layer interfaces and implementations are defined solely based on their observable behaviors. Our key idea is to leverage Reddy's pioneer work on modeling the semantics of imperative languages not as functions on global states but as objects with their observable behaviors. We show that a layer interface can be modeled as an object type (i.e., a layer signature) plus an object strategy. A layer implementation is then essentially a regular map, in the sense of Reddy, from an object with the underlay signature to that with the overlay signature. A layer implementation is certified when its composition with the underlay object strategy implements the overlay object strategy. We also describe an extension that allows for non-determinism in layer interfaces. After formulating layer implementations as regular maps between object spaces, we move to concurrency and design a notion of concurrent object space, where sequential traces may be identified modulo permutation of independent operations. We show how to express protected shared object concurrency, and a ticket lock implementation, in a simple model based on regular maps between concurrent object spaces

Aller mieux

Explorer les représentations et les pratiques de « l’aller mieux » dans le domaine de la santé et de la santé mentale plus particulièrement, tel est l’objectif général de cet ouvrage dont les contributions portent sur les dynamiques, les acteurs, les ressources concrètes et le vécu de la guérison, du rétablissement, du « s’en sortir ». Souvent psychologisés ou naturalisés, les processus de l’aller-mieux sont ici analysés comme un objet à part entière de la sociologie qui livre sur eux des éclairages nouveaux. Ces processus s’inscrivent au croisement de plusieurs domaines, celui des institutions du « normal » et du « pathologique », des politiques de soin et de care, de l’éthique et de l’existentiel. Aussi l’ouvrage donne-t-il la parole à des philosophes, des professionnels, des patients, ainsi qu’à des innovateurs, en présentant les expériences actuelles de pair-aidance en France ou dans d’autres pays.This book explores the representations and practices aiming at “doing better”, in the context of health, and more specifically mental health.Contributors focus on dynamics, actors, practical resources, and experience of healing, recovery, ways and means to get through