Fpm Frank Stappers

Formalizing a domain specific language using SOS: an industrial case study

This paper describes the process of formalizing an existing, industrial domain specific language (DSL) that is based on the task-resource paradigm. Initially, the semantics of this DSL is defined informally and implicitly through an interpreter. The formalization starts by projecting the existing concrete syntax onto a formal abstract syntax that defines the language operators and process terms. Next, we define the dynamic operational semantics at the level of individual syntactical notions, using structural operational semantics (SOS) as a formal meta-language. Here, the impact of the formalization process on the DSL is considered in terms of disambiguation of underlying (semantic) language design decisions.

Transforming SOS specifications to linear processes

This paper describes an approach to transform Structural Operational Semantics, given as a set of deduction rules, to a Linear Process Specification. The transformation is provided for deduction rules in De Simone format, including predicates. The Linear Process Specifications are specified in the syntax of the mCRL2 language, that, with help of the underlying (higher-order) re-writer/tool-set, can be used for simulation, labeled transition system generation and verification of behavioral properties. We illustrate the technique by showing the effect of the transformation from the Structural Operational Semantics specification of a simple process algebra to a Linear Process Specification.

Verification of safety requirements for program code using data abstraction

Large systems in modern development consist of many concurrent processes. To prove safety properties formal modelling techniques are needed. When source code is the only available documentation for deriving the systems behaviour, it is a difficult task to create a suitable model. Implementations of a system usually describe behaviour in too much detail for a formal verification. Therefore automated methods are needed that directly abstract from the implementation, but maintain enough information for a formal system analysis. This paper describes and illustrates a method by which systems with a high degree of parallelism can be verified. The method consists of creating an over-approximation of the behaviour by abstracting from the values of program variables. The derived model, consisting of interface calls between processes, is checked for various safety properties with the mCRL2 tool set.

Suitability of mCRL2 for concurrent-system design: a 2 × 2 switch case study

Specifying concurrent systems can be done using a variety of languages. These languages have different features and therefore are not necessarily equally suitable for capturing concepts from reality with respect to both expressivity and ease-of-use. This paper addresses these aspects for the specification language mCRL2 by considering the 2 × 2 Switch case study. This case study has been used before to compare other specification languages, more specifically TLA+, Bluespec, Statecharts and ACP. The case study primarily focuses on two important features, namely multi-party communication and priority of certain actions over other actions. We show that mCRL2 is appropriate for the specification of these features, especially multiparty communication. Moreover, we express some of the requirements of the original case study in terms of modal µ-calculus formulae and establish that these are indeed satisfied by the model.