A Formal Semantics for the SmartFrog Configuration Language

System configuration languages are now widely used to drive the deployment and evolution of large computing infrastructures. Most such languages are highly informal, making it difficult to reason about configurations, and introducing an important source of failure. We claim that a more rigorous approach to the development and specification of these languages will help to avoid these difficulties and bring a number of additional benefits. In order to test this claim, we present a formal semantics for the core of the SmartFrog configuration language. We demonstrate how this can be used to prove important properties such as termination of the compilation process. To show that this also contributes to the practical development of clear and correct compilers, we present three independent implementations, and verify their equivalence with each other, and with the semantics. Supported by an extended example from a real configuration scenario, we demonstrate how the process of developing the semantics has improved understanding of the language, highlighted problem areas, and suggested alternative interpretations. This leads us to advocate this approach for the future development of practical configuration languages

A membrane computing framework for self-reconfigurable robots

Self-reconfigurable robots are built by modules which can move in relationship to each other, which allows the robot to change its physical form. Finding a sequence of module moves that reconfigures the robot from the initial configuration to the goal configuration is a hard task and many control algorithms have been proposed. In this paper, we present a novel method which combines a cluster-flow locomotion based on cellular automata together with a decentralized local representation of the spatial geometry based on membrane computing ideas. This new approach has been tested with computer simulations and real-world experiments performed with modular self-reconfigurable robots and represents a new point of view with respect other control methods found in the literature.National Natural Science Foundation of China U1713201State Key Laboratory of Robotics 2018-O1

A CSP model with flexible parallel termination semantics

In the original failure-divergence semantic model for Communicating Sequential Processes (CSP), the incomplete treatment of successful process termination, and in particular parallel termination, permitted unnatural processes to be defined. In response to these problems, a number of different solutions have been proposed by various authors since the original failure-divergence model was developed by Hoare, Brookes and Roscoe. This paper presents an alternative solution to this problem, which is both closer to the original semantic model and provides greater flexibility over the type of parallel termination semantics available in CSP

Using a Process Algebra to control B OPERATIONS

The B-Method is a state-based formal method that describes system behaviour in terms of MACHINES whose state changes under OPERATIONS. The process algebra CSP is an event-based formalism that enables descriptions of patterns of system behaviour. This paper is concerned with the combination of these complementary views, in which CSP is used to describe the control executive for a B Abstract System. We discuss consistency between the two views and how it can be formally established. A typical avionics system motivates the work. Its specification and control executive are presented in the paper. The relationship with other approaches is also discussed. Keywords: B-Method, CSP, Embedded Systems, Programming Calculi, Combining Formalisms. CONTENTS 2 Contents 1 Introduction 3 2 Overview of the B-Method 3 3 Overview of the correspondence between Action Systems and CSP 4 4 A new coupling between B and CSP loops 6 4.1 Developing a Control Executive 7 4.2 Consistency of a CSP Control Executi..