We propose diagrammatic techniques for visualizing relational reasoning in formal methods like B or Z; in particular for induction and coinduction. These are similar to those for functional diagrams in category theory and inspired by rewriting theory. Diagrams are endowed with a simple algebraic semantics that imposes a convenient balance between expressive and algorithmic power. This makes the approach particularly suitable for mechanization and automation. Its usefulness for visual reasoning is illustrated by various examples. 相似文献
Coding no longer represents the main issue in developing software applications. It is the design and verification of complex software systems that require to be addressed at the architectural level, following methodologies which permit us to clearly identify and design the components of a system, to understand precisely their interactions, and to formally verify the properties of the systems. Moreover, this process is made even more complicated by the advent of the “network-centric” model of computation, where open systems dynamically interact with each other in a highly volatile environment. Many of the techniques traditionally used for closed systems are inadequate in this context.We illustrate how the problem of modeling and verifying behavioural properties of open system is addressed by different research fields and how their results may contribute to a common solution. Building on this, we propose a methodology for modeling and verifying behavioural aspects of open systems. We introduce the IP-calculus, derived from the π-calculas process algebra so as to describe behavioural features of open systems. We define a notion of partial correctness, acceptability, in order to deal with the intrinsic indeterminacy of open systems, and we provide an algorithmic procedure for its effective verification. 相似文献
In this paper a concept of probability defined on a Lukasiewicz-Moisil algebra is proposed. We take some steps in developing
the theory, including an extension theorem and some results related to conditional probabilities on Lukasiewicz-Moisil algebras. 相似文献
In this work we introduce Bio-PEPA, a process algebra for the modelling and the analysis of biochemical networks. It is a modification of PEPA to deal with some features of biological models, such as stoichiometry and the use of generic kinetic laws. Bio-PEPA may be seen as an intermediate, formal, compositional representation of biological systems, on which different kinds of analysis can be carried out. Finally, we show a representation of a model, concerning a simple genetic network, in the new language. 相似文献
This paper describes an adaptation of statecharts to take advantage of process algebra operators like those found in CSP and
EB3. The resulting notation is called algebraic state transition diagrams (ASTDs). The process algebra operators considered include sequence, iteration, parallel composition, and quantified synchronization.
Quantification is one of the salient features of ASTDs, because it provides a powerful mechanism to precisely and explicitly
define cardinalities in a dynamic model. The formal semantics of ASTDs is expressed using the operational style typically
used in process algebras. The target application domain is the specification and implementation of information systems. 相似文献
We illustrate the use of recently developed proof techniques for weak bisimulation by analysing a generic framework for the definition of distributed abstract machines based on a message-passing implementation. We first define this framework, and then focus on the algorithm which is used to route messages asynchronously to their destination.A first version of this algorithm can be analysed using the standard bisimulation up to expansion proof technique. We show that in a second, optimised version, rather complex behaviours appear, for which more sophisticated techniques, relying on termination arguments, are necessary to establish behavioural equivalence. 相似文献
Many attempts1, 7, 8, 35 have been made to overcome the limit imposed by the Turing Machine34 to realise general mathematical functions and models of (physical) phenomena.
They center around the notion of computability.
In this paper we propose a new definition of computability which lays the foundations for a theory of cybernetic and intelligent machines in which the classical limits imposed by discrete algorithmic procedures are offset by the use of continuous operators on unlimited data. This data is supplied to the machine in a totally parallel mode, as a field or wave.
This theory of machines draws its concepts from category theory, Lie algebras, and general systems theory. It permits the incorporation of intelligent control into the design of the machine as a virtual element. The incorporated control can be realized in many (machine) configurations of which we give three:
a) a quantum mechanical realization appropriate to a possible understanding of the quantum computer and other models of the physical microworld,
b) a stochastic realization based on Kolmogorov-Gabor theory leading to a possible understanding of generalised models of the physical or thermodynamic macroworld, and lastly
c) a classical mechanical realization appropriate lo the study of a new class of robots.
Particular applications at a fundamental level are cited in geometry, mathematics, biology, acoustics, aeronautics, quantum mechanics, general relativity and. Markov chains. The proposed theory therefore opens a new way towards understanding the processes that underlie intelligence. 相似文献