Abstract. A number of novel programming languages and libraries have been proposed that offer simpler-to-use models of concurrency than threads. It is challenging, however, to devise execution models that successfully realise their abstractions without forfeiting performance or introducing unintended behaviours. This is exemplified by Scoop-a concurrent object-oriented message-passing language-which has seen multiple semantics proposed and implemented over its evolution. We propose a "semantics workbench" with fully and semi-automatic tools for Scoop, that can be used to analyse and compare programs with respect to different execution models. We demonstrate its use in checking the consistency of semantics by applying it to a set of representative programs, and highlighting a deadlock-related discrepancy between the principal execution models of the language. Our workbench is based on a modular and parameterisable graph transformation semantics implemented in the Groove tool. We discuss how graph transformations are leveraged to atomically model intricate language abstractions, and how the visual yet algebraic nature of the model can be used to ascertain soundness.

The recently introduced notion of Modeling Spider Diagrams immerses Spider Diagrams in a modelling context. We enhance here their capabilities by including references to resources that are required to persist in some state or to perform some state transition. To this end, we introduce a notion of annotation, which can be expressed through a restriction of Conceptual Spider Diagrams (extended over domains), where domains are partially ordered and predicate edges have to be consistent with this ordering. The resulting notion of Annotated Modeling Spider Diagrams can then be used to express constraints on the usage of resources, so that conformance to a policy can be verified with respect to resource availability. We provide additional options for user-modelling choices via a natural equivalent representation in terms of (classical) Spider Diagrams, restricted on the domain of interest, and the use of colour for domain identification