The Boolean differential calculus is used as a mathematical tool to perform a variable transformation which allows to obtain a synchronous model for any asynchronous network. This synchronous model is used to derive behavioural and structural test procedures for asynchronous networks.

We present in this article a precise security model for data confidentiality in the framework of ASP (Asynchronous Sequential Processes). ASP is based on active objects, asynchronous communications, and data-flow synchronizations. We extend it with security levels attached to activities (active objects) and transmitted data. We design a security model that guarantees data confidentiality within...

State feedback controllers can be used to restore predictable behavior of asynchronous sequential machines that are afflicted by a critical race. The present note presents necessary and sufficient conditions for the existence of such controllers. The controllers also assign a specified behavior to the controlled machine. Copyright ©IFAC 2002

Rule-based reasoning is an essential part of human intelligence prominently formalized in artificial research via logic programs. Describing complex objects as the composition elementary ones a common strategy computer science and general. The author has recently introduced sequential programs context logic-based analogical learning programming. Motivated by these applications, this paper we co...

A standard way of building concurrent systems is by composing several individual processes by product operators. We show that even the simplest notion of product operators (i.e. asynchronous products) suffices to increase the complexity of model checking simple logics like HennessyMilner (HM) logic and its extension with the reachability operator (EF-logic) from PSPACE to nonelementary. In part...

Embedded speciications in object-oriented (OO) languages such as Eiiel and Sather are based on a rigorous approach towards validation, compatibility and reusability of sequential programs. The underlying method of \design-by-contract" is based on Hoare logic for which concurrency extensions exist. However concurrent OO languages are still in their infancy. They have inherently imperative facets...

The various modes of failure of asynchronous sequential logic circuits due to timing problems are considered. These are hazards, critical races and metastable states. It is shown that there is a mechanism common to all forms of hazards and to metastable states. A similar mechanism, with added complications, is shown to characterize critical races. Means for defeating various types of hazards an...

We present a mathematical de nition of a hardware description language (HDL) that admits a semantics-preserving translation to a subset of VHDL. Our HDL includes the basic VHDL propagation delay mechanisms and gate-level circuit descriptions. We also develop formal procedures for deriving and verifying concise behavioral speci cations of combinational and sequential devices. The HDL and the spe...