Abstract. The analysis of complex distributed systems requires dedicated software tools. The mCRL2 language and toolset have been developed to support such analysis. We highlight changes and improvements made to the toolset in recent years. On the one hand, these affect the scope of application, which has been broadened with extended support for data structures like infinite sets and functions. On the other hand, considerable progress has been made regarding the performance of our tools for state space generation and model checking, due to improvements in symbolic reduction techniques and due to a shift towards parity gamebased solving. We also discuss the software architecture of the toolset, which was well suited to accommodate the above changes, and we address a number of case studies to illustrate the approach.

Abstract. This paper describes an approach to transform a 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 and extended to incorporate predicates. The Linear Process Specifications are specified in syntax of the language mCRL2, that, with help of the underlying (higher-order) re-writer/toolset, can be used for simulation, labelled transition system generation and verification of behavioural properties. We illustrate the technique by showing the effect of the transformation from the Structural Operational Semantics specification of a simple process algebra to aLinear Process Specification.

Abstract. This paper describes the process of formalizing an existing, industrial domain specific language (dsl) that is based on the taskresource 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 metalanguage. Here, the impact of the formalization process on the dsl is considered in terms of disambiguation of underlying (semantic) language design decisions.

This paper presents practices and experiences in developing the formal methods toolset mCRL2. Findings are presented based on years of experiences in developing tools in an academic environment. Practical problems and ways to solve them are discussed. We also present the direction that we foresee for the coming years of development in formal methods tool support. Copyright © 2010 John Wiley & Sons, Ltd.

Abstract-The mCRL2 language is a formal specification language that is used to specify, model, analyze and verify behavioral properties for distributed systems and protocols. The semantics of the mCRL2 language is defined formally using Structural Operational Semantics (SOS). In [32] we propose an approach that takes the SOS of a formal language, along with a concrete model, that serves as an initialization, and transforms it to a Linear Process Specification (LPS). In this paper we extend the approach and show that it can be applied to a formal language that is actually used to specify and model discussed systems. Hence, we take mCRL2's own operational semantics and transform it into an mCRL2 specification. In essence, this means that we are feeding the mCRL2 toolset its own formal language definition. This semantic dogfooding approach validates the implemented behavior for the mCRL2 language against its formal definition. By performing this exercise we revealed gaps between the defined and implemented semantics. These gaps have subsequently been resolved.