In Software Abstractions Daniel Jackson introduces an approach to software design that draws on traditional formal methods but exploits automated tools to find flaws as early as possible. This approach--which Jackson calls "lightweight formal methods" or "agile modeling"--takes from formal specification the idea of a precise and expressive notation based on a tiny core of simple and robust concepts but replaces conventional analysis based on theorem proving with a fully automated analysis that gives designers immediate feedback. Jackson has developed Alloy, a language that captures the essence of software abstractions simply and succinctly, 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 to make models that are more precise and elegant. This approach, Jackson says, can rescue designers from "the tarpit of implementation technologies" and return them to thinking deeply about underlying 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 syntax to the logic for structuring descriptions; and an analysis, a form of constraint solving that offers both simulation (generating sample states and executions) and checking (finding counterexamples to claimed properties).

/pdf/software-abstractions-logic-language-and-analysis-3g5voq3xt7.pdf

Software Abstractions: Logic, Language, and Analysis

JML is a behavioral interface speci cation language tailored to Java It also allows assertions to be intermixed with Java code, as an aid to veri cation and debugging JML is designed to be used by working software engineers, and requires only modest mathematical training To achieve this goal, JML uses Ei el-style assertion syntax combined with the model-based approach to speci cations typi ed by VDM and Larch However, JML supports quanti ers, speci cation-only variables, frame conditions, and other enhancements that make it more expressive for speci cation than Ei el This paper discusses the goals of JML, the overall approach, and describes the language through examples It is intended for readers who have some familiarity with both Java and behavioral speci cation using preand postconditions

https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1123&context=cs_techreports

Preliminary Design of JML: A Behavioral Interface Specification

Behavioral interface specification languages provide formal code-level annotations, such as preconditions, postconditions, invariants, and assertions that allow programmers to express the intended behavior of program modules. Such specifications are useful for precisely documenting program behavior, for guiding implementation, and for facilitating agreement between teams of programmers in modular development of software. When used in conjunction with automated analysis and program verification tools, such specifications can support detection of common code vulnerabilities, capture of light-weight application-specific semantic properties, generation of test cases and test oracles, and full formal program verification. This article surveys behavioral interface specification languages with a focus toward automatic program verification and with a view towards aiding the Verified Software Initiative—a fifteen-year, cooperative, international project directed at the scientific challenges of large-scale software verification.

/pdf/behavioral-interface-specification-languages-32rs4k0ufk.pdf

Behavioral interface specification languages

Overture is a community-based initiative that aims to develop a common open-source platform integrating a range of tools for constructing and analysing formal models of systems using VDM. The mission is to both provide an industrial-strength tool set for VDM and also to provide an environment that allows researchers and other stakeholders to experiment with modifications and extensions to the tools and language. This paper presents the current status and future vision of the Overture project.

The overture initiative integrating tools for VDM

We describe the current status of "VDMTools", a group of tools supporting the analysis of system models expressed in the formal language of the Vienna Development Method. Three dialects of the language are supported: the ISO standard VDM specification language with support for modular structuring, the extension VDM++ which supports object-oriented structuring and concurrency, and a version extending VDM++ with features for modeling and analysing distributed embedded real-time systems. VDMTools provides extensive static semantics checking, automatic code generation, roundtrip mapping to UML class diagrams, documentation support, test coverage analysis and debugging support. The tools' focus is on supporting the cost-effective development and exploitation of formal models in industrial settings. The paper presents the components of VDMTools and reports recent experience using them for the development of large models.

VDMTools: advances in support for formal modeling in VDM

Information technology - Programming languages, their environments and system software interfaces: Vienna DevelopmentMethod - Specification Language - Part 1: Base language

The work presented here concerns abstract specification of type checking for a specification language VDM-SL of the Vienna Development Method. Where previous work has focussed on rejection of “obviously” ill-typed specifications we do, in addition, consider acceptance of “obviously” well-typed expressions.

An Approach to the Static Semantics of VDM-SL

Some specification languages, such as VDM-SL, allow expressions whose values are not fully determined. This may be convenient in cases where the choice of value should be left to a later stage of development.

We consider a simple functional language including such under-determined expressions and present a denotational semantics for the language along with a set of proof rules for reasoning about properties of under-determined expressions. One of the specific problems considered is the combination of under-determinedness and a least fixed point semantics of recursion. Soundness of the proof rules is also discussed.

Semantics of under-determined expressions

Im klassischen relationalen Daten-Modell wird ublicherweise die erste Normalform (INF) zwingend vorgeschrieben /Cod,Dat/ Diese Forderung ist keine fur die Relationentheorie unabdingbare Voraussetzung /Ull/, wohl aber eine betrachtliche Vereinfachung Es hat in der Vergangenheit nicht an Ansatzen fur Datenmodelle gefehlt, die unnormalisierte Relationen zulassen /BFP, Mak, Kob/ Sie entwickelten sich insbesondere dort, wo die Einfachheit des klassischen relationalen Modells als Beschrankung empfunden wurde, etwa bei der Verwaltung technisch-wissenschatlicher Daten /Erb, LoPl/, bei “form models” fur Buroinformationssysteme /LY, SLCT, Tsi/, oder in der integrierten Verwaltung formatierter und unformatierter (Text-)Daten /Sch/ Fur diese Anwendungen bietet sich als ubergreifendes Datenmodell das tabellenorientierte NF2-Modell /SchP/ an

Eine sequelartige Sprachschnittstelle für das NF2-Modell

The variants of specification languages used with the Vienna Development Method (VDM) offer a rather expressive notion of types. Higher order function types, recursively defined types, and a notion of union types which does not require injection and projection are all included, not to mention subtypes characterized by arbitrary predicates.

Bo Stig Hansen

Papers

Information technology - Programming languages, their environments and system software interfaces: Vienna DevelopmentMethod - Specification Language - Part 1: Base language

An Approach to the Static Semantics of VDM-SL

Semantics of under-determined expressions

Eine sequelartige Sprachschnittstelle für das NF2-Modell

On Type Checking in VDM and Related Consistency Issues