Correctness of realizations of levels of abstraction in Operating Systems -- A simulation model representing the OS/VS2 Release 2 Control Program -- Une analyse de systeme par typologie -- Equivalence and decomposition methods with application to a model of a time-sharing virtual memory system -- The specification of process synchronization by path expressions -- A foreground-background time sharing queue with general service times -- Espace d'adressage et espace d'exécution du systeme gemau -- A new approach to avoidance of system deadlocks -- A program structure for error detection and recovery -- Analyse de quelques pannes d'un systeme d'exploitation -- An open operating system for a single-user machine -- Evaluation sur des modeles de comportement de programme de la taille d'un ensemble de travail -- Schedulers as enforces in synchronization processes -- Caractérisation fonctionnelle des systemes de fichiers -- Presentation of the control graph models -- The Edinburgh Multi-Access System scheduling and allocation procedures in the resident supervisor.