The Anna approach to specification language design strengthens the existing explanatory constructs in Ada and adds new ones where there is an obvious need.
Clock synchronization algorithms play a crucial role in a variety of fault-tolerant distributed architectures. Although those algorithms are similar in their basic structure, the particular designs diier considerably , for instance in the way clock adjustments are computed. This paper develops a formal generic theory of clock synchronization algorithms… (More)
We describe our experience with formal, machine-checked verification of algorithms for critical ap-, placations, concentrating on a Byzantine fault-tolerant algorithm for synchronizing the clocks in the replicated computers of a digit al flight control system. First, we explain the problems encountered in unsynchronized systems and the necessity, and… (More)
This paper describes our experience using coordinated atomic (CA) actions as a system structuring tool to design and validate a sophisticated control system for a complex industrial application that has high reliability and safety requirements. Our study is based on the "Fault-Tolerant Production Cell", which represents a manufacturing process involving… (More)
We describe a formal speciication and mechanically checked veriica-tion of the Interactive Convergence Clock Synchronization Algorithm of Lamport and Melliar-Smith 16]. In the course of this work, we discovered several technical aws in the analysis given by Lamport and Melliar-Smith, even though their presentation is unusually precise and detailed. As far… (More)
This work is motivated by experiences in the course of developing an ontology-based application within a real-world setting. We found out that current benchmarks are not well suited to provide helpful hints for users who seek for an appropriate reasoning system able to deal with expressive terminological descriptions, large volumes of asser-tional data, and… (More)