Combining interaction and automation in process algebra verification

Abstract

Most existing verification tools for process algebras allow the correctness of specifications to be checked in a fully automatic fashion. These systems have the obvious advantage of being easy to use, but unfortunately they also have some drawbacks. In particular, they do not always succeed in completing the verification analysis, due to the problem of state explosion, and they do not provide any insight into the meaning of the intended specifications. In this paper we consider an alternative approach in which both interactive and automatic techniques are combined in the hope that the advantages of automation are retained, and that some of its disadvantages are overcome. To achieve our goal, we use the interactive theorem prover ItOL as a framework for supporting the theory of observational congruence of ccs, and provide a set of automatic proof tools, based on the algebraic axiomatization of the language, which can be used interactively. To illustrate how interaction and automation can be intermixed, we describe two verification strategies which exhibit different degrees of user interaction.

A Generic Theorem Prover of CSP Refinement

“…In this Section, we concentrate on how to encode cms and restriction spaces. Trace theory is similar to the data type of lists 6 . The discussion of the syntax definition is postponed to Sect.…”

“…Alternative to encoding a denotational semantics, [6,19,1] base their encodings on an axiomatic semantics of the process algebra. As discussed in Sect.…”

Mechanizing a proof by induction of process algebra specifications in higher order logic

“…It has been used to mechanize several logics [8] and process algebras, e.g. csP [1,2] and ccs [3]. The theorem prover used in these mechanizations is the HOL system [7], developed by Gordon, which is based directly on the LCF theorem prover [14].…”

“…In this section, we recall briefly some aspects about the formalization of pure ccs in HOL; the reader should refer to [3] for more details about the mechanization of the axioms.…”

“…In [3,6] a verification environment which relies on the algebraic nature of the concurrent specification language cos [13], is described and fully motivated. Such an environment provides the user with facilities to control the analysis and verification phases and to perform proofs automatically.…”