Automatic Visualization of Relational Logic Models

Abstract: The Alloy Analyzer is a software design tool that generates examples of system states and executions from logic models and displays those examples graphically with a visualization facility. Although many users find the visualization indispensable, others are put off by the perceived difficulty of customizing the visualization and the poor quality of default diagrams. Many others do not take full advantage of the customization, usually because they do not understand what customizations are available and how best to apply them. This paper describes techniques for inferring a better initial customization, or theme, entirely automatically, based on the model and on criteria derived from experience with manual customization. A plugin that implements these techniques was applied to a repertoire of models. Each automatically generated theme was compared to an "expert" theme and to the default theme, with a simple metric that quantifies the visual difference between themes. These comparisons, which provide an indication of how closely the plugin can match the expert result, show the generated theme to be superior to the default for most models

ALDB: Debugging Alloy Models of Behavioural Requirements

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Declarative modelling languages, such as Alloy, are becoming popular for describing behavioural requirements very early in system development because automated analysis of these models provides valuable feedback. Typically, these languages are supported by constraint solvers (SAT, SMT) for providing instances or model checking properties. However, a user can quickly find simple bugs and gain confidence in their model by concretely simulating steps of the transition system. We present ALDB: a debugger for models of transition systems written in the Alloy language. It provides a familiar debugging interface to walk around in the behaviour of the model, enabling users to quickly explore scenarios, find errors via concrete simulation, and incrementally build up to bounded model checking.Natural Sciences and Engineering Research Council of Canada