GUESSING, MODEL CHECKING AND THEOREM PROVING OF STATE MACHINE PROPERTIES – A CASE STUDY ON QLOCK

It is worth understanding state machines better because various kinds of systems can be formalized as state machines and therefore understanding state machines has something to do with comprehension of systems. Understanding state machines can be interpreted as knowing properties they enjoy and comprehension of systems is interpreted as knowing whether they satisfy requirements. We (mainly the second author) have developed a tool called SMGA that basically takes a finite sequence of states from a state machine and generates a graphical animation of the finite sequence or the state machine. Observing such a graphical animation helps us guess properties of the state machine. We should confirm whether the state machine enjoys the guessed properties because such guessed properties may not be true properties of the state machine. Model checking is one possible technique to do so. If the state machine has a fixed small number of reachable states, model checking is enough. Otherwise, however, it is not. If that is the case, we should use some other techniques to make sure that the system enjoys the guessed properties. Interactive theorem proving is one such technique. The paper reports on a case study in which a mutual exclusion protocol called Qlock is used as an example to exemplify the abovementioned idea or methodology

Research on Highly Reliable Agile Formal Engineering Methods

研究成果の概要 (和文) : 本研究では、既存のソフトウェア開発手法の短所を大幅に改善して、生産性と信頼性を共に確保する最新のソフトウェア開発技術とした「SOFLアジャイル形式工学手法」を確立して、次の具体的な成果を達成した。（１）SOFLアジャイル形式工学手法のフレームワーク、（２）SOFL仕様のアニメーション化手法、（３）仕様アニメーションとプログラムのテスト用のテストデータの自動生成手法とアルゴリズム、（４）定理証明とモデル検査の融合技術とアニメーション化手法,（５）仕様アニメーションの可視化表現手法、（６）仕様アニメーションの支援ツールとテストデータの自動生成の支援ツールのプロトタイプの開発。研究成果の概要 (英文) : In this research, we have established a new technology known as SOFL Agile Formal Engineering Method that significantly improves the existing software development methods in terms of offering a great capability of enhancing both software productivity and reliability. Specifically, the technology includes the following aspects:(1) a framework of the SOFL Agile Formal Engineering Method, (2) a new method for carrying out the animation of hybrid specifications, (3) a new method and the related algorithms for automatically generating test data for both specification animation and specification-based program testing, (4) a method for combining theorem proving with model checking and a tool support for model checking process animation, (5) prototypes of software tools to support the automatic test data generation for both specification animation and specification-based program testing

Graphical Animations of State Machines [課題研究報告書]

Supervisor:緒方　和博情報科学研究科修