Real-Time Maude Tool Research Articles

Adaptive-Step-Size Numerical Methods in Rewriting-Logic-Based Formal Analysis of Interacting Hybrid Systems

This paper focuses on the formal modeling, simulation, and analysis of interacting hybrid systems that influence each otherʼs continuous behaviors. We define in the rewriting-logic-based Real-Time Maude tool a method for the numerical approximation of the continuous dynamics specified by ordinary differential equations. We adapt the Runge-Kutta-Fehlberg 4/5 method to define an adaptive-step-size technique that allows a more accurate approximation with less computational effort than fixed-step-size techniques. We also present experimental results for two thermal systems using different error tolerances.

A Guide to Extending Full Maude Illustrated with the Implementation of Real-Time Maude

The goal of this paper is to serve as a practical guide for implementing extensions of Maude by giving an overview of how the Real-Time Maude tool has been developed by extending the implementation of Full Maude. After giving a high-level summary of the key functionality and structure of the implementation of Full Maude, we describe the implementation of the Real-Time Maude language and tool. This extension includes key issues such as adding new kinds of modules, rules, and commands; as well as the need to store additional information in the persistent state of the execution environment.

Specification and analysis of the AER/NCA active network protocol suite in Real-Time Maude

This paper describes the application of the Real-Time Maude tool and the Maude formal methodology to the specification and analysis of the AER/NCA suite of active network multicast protocol components. Because of the time-sensitive and resource-sensitive behavior, the presence of probabilistic algorithms, and the composability of its components, AER/NCA poses challenging new problems for its formal specification and analysis. Real-Time Maude is a natural extension of the Maude rewriting logic language and tool for the specification and analysis of real-time object-based distributed systems. It supports a wide spectrum of formal methods, including: executable specification; symbolic simulation; breadth-first search for failures of safety properties in infinite-state systems; and linear temporal logic model checking of time-bounded temporal logic formulas. These methods complement those offered by network simulators on the one hand, and timed-automaton-based tools and general-purpose theorem provers on the other. Our experience shows that Real-Time Maude is well-suited to meet the AER/NCA modeling challenges, and that its methods have proved effective in uncovering subtle and important errors in the informal use case specification.

Real-Time Maude: A Tool for Simulating and Analyzing Real-Time and Hybrid Systems

Rewriting logic can be used to specify a wide range of real-time and hybrid systems under a variety of time models, including discrete and dense time models. The Real-Time Maude tool, built on top of the Maude rewriting logic language, supports specification of real-time and hybrid systems in timed modules and timed object-oriented modules, which are transformed into equivalent Maude modules. The tool then supports execution of such specifications in several rewrite modes, corresponding to different criteria for advancing time. Besides system simulation by default execution in a given rewrite mode, the tool has a library of execution strategies and commands that can search all the possible computations from an initial state, within given rewrite mode and search bounds, to partially model check desired properties, including properties expressible in a class of linear time timed temporal logic formulas. The paper discusses the tool's theoretical basis, its specification language, and its library of evaluation and search strategies. The user can add new formal analysis strategies to the library, as illustrated by a scheduling case study. We also summarize our experience with applications and our future plans.