Towards the Construction of an Abstract State-Space from a Partial-Order Representation of the Concrete One

When analysing a concurrent program in order to verify its correctness one faces a severe complexity problem: state-spaces corresponding to concurrent programs become tremendously large. To cope with this problem of state-space explosion, two differenttypes of approaches have been established: abstraction techniques and partial-order methods. Abstraction aims at reducing the number of states by reducing the diversity of actions of a program. Partial-order methods reduce a state-space by ignoring particular interleavings of concurrent behavioural patterns. However, abstraction still faces the intricateness of an exhaustive state-space construction and partial-order methods, by ignoring certain patterns of actions, are not suitable for proving some property classes such..

Computer assisted manipulation of algebraic process specifications

Specifications of sytem behaviour tend to become large. Analysis of such specifications requires automated tools. Most attention hitherto has been invested in fully automatic tools. We however believe that in many cases human intervention is required and we therefore propose a number of computer tools to transform process specifications. The concrete manipulation tools that we describe can eliminate constants, redundant sum variables and parameters, and allow to split variables ranging over compex datatypes. These tools can transform specifications with large finite state spaces to variants with state spaces being a fraction of their original size, and transform specifications wich infinite state spaces to those with finite state spaces

Questions and Answers About Ten Formal Methods

An abstract model of an industrial distributed data base application has been studied using process based, state based, and queueing theory based methods. The methods supported by graphical notations and/or integrated development environments were found to be easiest to work with. The methods supported by model checkers were the most successful in obtaining relevant information about the application. Applying a number of different methods to study one particular model encourages a problem to be viewed from different angles. This gives complementary information about the model. We report on a variety of problems of the model found through various routes. Our main conclusion is that asking experts to apply different methods and tools at a sufficiently abstract level can be done effectively revealing a broad range of information about the considered application