The bounded retransmission protocol revisited (extended abstract, revised July 1, 1999)

AbstractWe demonstrate the use of abstract interpretation techniques in model checking by verifying Philips' Bounded Retransmission Protocol for all parameter instances

Almost Linear B\"uchi Automata

We introduce a new fragment of Linear temporal logic (LTL) called LIO and a new class of Buechi automata (BA) called Almost linear Buechi automata (ALBA). We provide effective translations between LIO and ALBA showing that the two formalisms are expressively equivalent. While standard translations of LTL into BA use some intermediate formalisms, the presented translation of LIO into ALBA is direct. As we expect applications of ALBA in model checking, we compare the expressiveness of ALBA with other classes of Buechi automata studied in this context and we indicate possible applications

Handling Conflicts in Depth-First Search for LTL Tableau to Debug Compliance Based Languages

Providing adequate tools to tackle the problem of inconsistent compliance rules is a critical research topic. This problem is of paramount importance to achieve automatic support for early declarative design and to support evolution of rules in contract-based or service-based systems. In this paper we investigate the problem of extracting temporal unsatisfiable cores in order to detect the inconsistent part of a specification. We extend conflict-driven SAT-solver to provide a new conflict-driven depth-first-search solver for temporal logic. We use this solver to compute LTL unsatisfiable cores without re-exploring the history of the solver.Comment: In Proceedings FLACOS 2011, arXiv:1109.239

A timed failures model for extended communicating processes:extended abstract

We develop a model for the real-time behaviour of an extension of communicating sequential processes, ECP: the timed failures model. ECP includes a time-out mechanism for actions that synchronize and a broadcast construct. The model maximalizes local activity in processes and allows the delay of enabled synchronization actions to be a-priori bounded. It is a direct generalization of the (non-timed) failures model: traces are generalized to time-action relations, associating actions to the times at which they occur, and failure-sets to time-failure relations, associating actions to the times at which they are refused. In addition to a-priori bounded delay of actions, the model supports nondiscrete time and concurrency of actions; it makes the semantic operators continuous and is fully abstract when actions and the times at which they take place are made observable.\u3cbr/\u3e\u3cbr/\u3e\u3cbr/\u3e\u3cbr/\u3

A compositional proof theory for fault tolerant real-time distributed systems

A compositional network proof theory for specifying and verifying fault tolerant real-time distributed systems is presented. Important in such systems is the failure hypothesis that stipulates the class of failures that must be tolerated. In the formalism presented, the failure hypothesis of a system is represented by a predicate which expresses how faults might transform the behavior of the system. The approach is illustrated by investigating a triple modular redundant system