4 research outputs found
An LTL Semantics of Business Workflows with Recovery
We describe a business workflow case study with abnormal behavior management
(i.e. recovery) and demonstrate how temporal logics and model checking can
provide a methodology to iteratively revise the design and obtain a correct-by
construction system. To do so we define a formal semantics by giving a
compilation of generic workflow patterns into LTL and we use the bound model
checker Zot to prove specific properties and requirements validity. The working
assumption is that such a lightweight approach would easily fit into processes
that are already in place without the need for a radical change of procedures,
tools and people's attitudes. The complexity of formalisms and invasiveness of
methods have been demonstrated to be one of the major drawback and obstacle for
deployment of formal engineering techniques into mundane projects
A temporal logic for micro- and macro-step-based real-time systems: Foundations and applications
Many systems include components interacting with each other that evolve at possibly very different speeds. To deal with this situation many formal models adopt the abstraction of “zero-time transitions”, which do not consume time. These, however, have several drawbacks in terms of naturalness and logic consistency, as a system is modeled to be in different states at the same time. We propose a novel approach that exploits concepts from non-standard analysis and pairs them with the traditional “next” operator of temporal logic to introduce a notion of micro- and macro-steps; our approach is enacted in an extension of the TRIO metric temporal logic, called X-TRIO. We study the expressiveness and decidability properties of the new logic. Decidability is achieved through translation of a meaningful subset of X-TRIO into Linear Temporal Logic, a traditional way to support automated verification. We illustrate the usefulness and the generality of our approach by applying it to provide a formal semantics of timed Petri nets, which allows for their automated verification. We also give an overview of a formal semantics of Stateflow/Simulink diagrams, defined in terms of X-TRIO, which has been applied to the automated verification of a robotic cell
A Metric Temporal Logic for Dealing with Zero-Time Transitions
Many industrial systems include components interacting with each other that evolve with possibly very different speeds. To deal with this situation many formalisms adopt the abstraction of ``zero-time transitions'', which do not consume time. These, however, have several drawbacks in terms of naturalness and logic consistency, as a system is modeled to be in different states at the same time. We introduce a metric temporal logic, called X-TRIO, that uses non-standard analysis to elegantly deal with zero-time transitions in an abstract, descriptive way. We study the decidability of the logic, and we introduce a decision procedure for a subset thereof. X-TRIO has been applied in companion works to the design and verification of industrial systems