Declarative behavioural modelling is a powerful modelling paradigm that enables users to model system functionality abstractly and concisely. We compare two well-used formal declarative modelling languages, B and TLA + , with a new modelling language called Dash. Dash is an extension of Alloy with explicit syntactic constructs for modelling transition systems, and it includes control state hierarchy and events. Particular topics that we cover in our comparison are: differences in the datatypes and type systems; how the transitions/operations can be described; how the transition relation is a combination of the transitions; and the default choice each language makes regarding permitted variable changes in a transition. Our goal is to discuss the interesting differentiating characteristics of each language to aid users in determining which language is the most suitable for their system.

Declarative behavioural modelling is a powerful modelling paradigm that enables users to model system functionality abstractly and formally using constraints. There are several different formal declarative languages and they have greatly varying constructs for representing a transition system, and they sometimes differ in rather subtle ways. We qualitatively compare seven formal declarative modelling languages B, Event-B, Alloy, Dash, TLA+, PlusCal, and Asmetal, with respect to three main categories: structuring transition systems (control modelling), data descriptions in transition systems (data modelling), and modularity aspects of modelling. We developed this comparison by completing a set of case studies across the data- vs. control-oriented spectrum of models in all of the above languages. We present recommendations based on our observations about the differentiating characteristics of each of these languages to help modellers answer the important question of which declarative modelling language may be most suitable for modelling their system.

Declarative behavioural modelling is a powerful modelling paradigm that enables users to model system functionality abstractly and formally using constraints. There are several different formal declarative languages and they have greatly varying constructs for representing a transition system, and they sometimes differ in rather subtle ways. We qualitatively compare seven formal declarative modelling languages B, Event-B, Alloy, Dash, TLA+, PlusCal, and Asmetal, with respect to three main categories: structuring transition systems (control modelling), data descriptions in transition systems (data modelling), and modularity aspects of modelling. We developed this comparison by completing a set of case studies across the data- vs. control-oriented spectrum of models in all of the above languages. We present recommendations based on our observations about the differentiating characteristics of each of these languages to help modellers answer the important question of which declarative modelling language may be most suitable for modelling their system.