Software Abstractions: Logic, Language, and Analysis
In Software Abstractions Daniel Jackson introduces an approach tosoftware design that draws on traditional formal methods but exploits automated tools to find flawsas early as possible. This approach--which Jackson calls "lightweight formal methods" or"agile modeling"--takes from formal specification the idea of a precise and expressivenotation based on a tiny core of simple and robust concepts but replaces conventional analysis basedon theorem proving with a fully automated analysis that gives designers immediate feedback. Jacksonhas developed Alloy, a language that captures the essence of software abstractions simply andsuccinctly, using a minimal toolkit of mathematical notions. This revised edition updates the text,examples, and appendixes to be fully compatible with the latest version of Alloy (Alloy 4).
The designer can use automated analysis not only to correct errors but also tomake models that are more precise and elegant. This approach, Jackson says, can rescue designersfrom "the tarpit of implementation technologies" and return them to thinking deeply aboutunderlying concepts. Software Abstractions introduces the key elements: a logic,which provides the building blocks of the language; a language, which adds a small amount of syntaxto the logic for structuring descriptions; and an analysis, a form of constraint solving that offersboth simulation (generating sample states and executions) and checking (finding counterexamples toclaimed properties).