This paper describes a toolkit that assists in the task of generating abstract approximations of process algebraic specifications written in the language μCRL. Abstractions are represented by Modal Labelled Transition Systems, which are mixed transition systems with may and must modalities. The approach permits to infer the satisfaction or refutation of safety and liveness properties expressed in the (action-based) μ-calculus. The tool supports the abstraction of states and action labels, which allows to deal with infinitely branching systems.

Formal Methods in System Design
Specification and Analysis of Embedded Systems

Espada, M. V., & van de Pol, J. (2007). An abstract interpretation toolkit for $\mu$CRL. Formal Methods in System Design, 30(3), 249–273.