Formalizing graphical notations

The thesis describes research into graphical notations for software engineering, with a principal interest in ways of formalizing them. The research seeks to provide a theoretical basis that will help in designing both notations and the software tools that process them. The work starts from a survey of literature on notation, followed by a review of techniques for formal description and for computational handling of notations. The survey concentrates on collecting views of the benefits and the problems attending notation use in software development; the review covers picture description languages, grammars and tools such as generic editors and visual programming environments. The main problem of notation is found to be a lack of any coherent, rigorous description methods. The current approaches to this problem are analysed as lacking in consensus on syntax specification and also lacking a clear focus on a defined concept of notated expression. To address these deficiencies, the thesis embarks upon an exploration of serniotic, linguistic and logical theory; this culminates in a proposed formalization of serniosis in notations, using categorial model theory as a mathematical foundation. An argument about the structure of sign systems leads to an analysis of notation into a layered system of tractable theories, spanning the gap between expressive pictorial medium and subject domain. This notion of 'tectonic' theory aims to treat both diagrams and formulae together. The research gives details of how syntactic structure can be sketched in a mathematical sense, with examples applying to software development diagrams, offering a new solution to the problem of notation specification. Based on these methods, the thesis discusses directions for resolving the harder problems of supporting notation design, processing and computer-aided generic editing. A number of future research areas are thereby opened up. For practical trial of the ideas, the work proceeds to the development and partial implementation of a system to aid the design of notations and editors. Finally the thesis is evaluated as a contribution to theory in an area which has not attracted a standard approach

Extracting proofs from documents

Often, theorem checkers like PVS are used to check an existing proof, which is part of some document. Since there is a large difference between the notations used in the documents and the notations used in the theorem checkers, it is usually a laborious task to convert an existing proof into a format which can be checked by a machine. In the system that we propose, the author is assisted in the process of converting an existing proof into the PVS language and having it checked by PVS. 1 Introduction The now-classic ALGOL 60 report [5] recognized three different levels of language: a reference language, a publication language and several hardware representations, whereby the publication language was intended to admit variations on the reference language and was to be used for stating and communicating processes. The importance of publication language ---often referred to nowadays as "pseudo-code"--- is difficult to exaggerate since a publication language is the most effective way..

An automata-based automatic verification environment

With the continuing growth of computer systems including safety-critical computer control systems, the need for reliable tools to help construct, analyze, and verify such systems also continues to grow. The basic motivation of this work is to build such a formal verification environment for computer-based systems. An example of such a tool is the Design Oriented Verification and Evaluation (DOVE) created by Australian Defense Science and Technology Organization. One of the advantages of DOVE is that it combines ease of use provided by a graphical user interface for describing specifications in the form of extended state machines with the rigor of proving linear temporal logic properties in a robust theorem prover, Isabelle which was developed at Cambridge University, UK, and TU Munich, Germany. A different class of examples is that of model checkers, such as SPIN and SMV. In this work, we describe our technique to increase the utility of DOVE by extending it with the capability to build systems by specifying components. This added utility is demonstrated with a concrete example from a real project to study aspects of the control unit for an infusion pump being built at the Walter Reid Army Institute of Research. Secondly, we provide a formulation of linear temporal logic (LTL) in the theorem prover Isabelle. Next, we present a formalization of a variation of the algorithm for translating LTL into Büchi automata. The original translation algorithm is presented in Gerth et al and is the basis of model checkers such as SPIN. We also provide a formal proof of the termination and correctness of this algorithm. All definitions and proofs have been done fully formally within the generic theorem prover Isabelle, which guarantees the rigor of our work and the reliability of the results obtained. Finally, we introduce the automata theoretic framework for automatic verification as our future works

Facilitating the modelling and automated analysis of cryptographic protocols

Includes bibliographical references.Multi-dimensional security protocol engineering is effective for creating cryptographic protocols since it encompasses a variety of design, analysis and deployment techniques, thereby providing a higher level of confidence than individual approaches. SPEAR II, the Security Protocol Engineering and Analysis Resource n, is a protocol engineering tool built on the foundation of previous experience garnered during the SPEAR I project in 1997. The goal of the SPEAR II tool is to facilitate cryptographic protocol engineering and aid users in distilling the critical issues during an engineering session by presenting them with an appropriate level of detail and guiding them as much as possible. The SPEAR II tool currently consists of four components that have been created as part of this dissertation and integrated into one consistent and unified graphical interface: a protocol specification environment (GYPSIE), a GNY statement construction interface (Visual GNY), a Prolog-based GNY analysis engine (GYNGER) and a message rounds calculator

Proceedings of the 1994 Monterey Workshop, Increasing the Practical Impact of Formal Methods for Computer-Aided Software Development: Evolution Control for Large Software Systems Techniques for Integrating Software Development Environments

Office of Naval Research, Advanced Research Projects Agency, Air Force Office of Scientific Research, Army Research Office, Naval Postgraduate School, National Science Foundatio

Applications of formal methods in engineering

The main idea presented in this thesis is to propose and justify a general framework for the development of safety-related systems based on a selection of criticality and the required level of integrity. We show that formal methods can be practically and consistently introduced into the system design lifecycle without incurring excessive development cost. An insight into the process of generating and validating a formal specification from an engineering point of view is illustrated, in conjunction with formal definitions of specification models, safety criteria and risk assessments. Engineering specifications are classified into two main classes of systems, memoryless and memory bearing systems. Heuristic approaches for specification generation and validation of these systems are presented and discussed with a brief summary of currently available formal systems and their supporting tools. It is further shown that to efficiently address different aspects of real-world problems, the concept of embedding one logic within another mechanised logic, in order to provide mechanical support for proofs and reasoning, is practical. A temporal logic framework, which is embedded in Higher Order Logic, is used to verify and validate the design of a real-time system. Formal definitions and properties of temporal operators are defined in HOL and real-time concepts such as timing marker, interrupt and timeout are presented. A second major case study is presented on the specification a solid model for mechanical parts. This work discusses the modelling theory with set theoretic topology and Boolean operations. The theory is used to specify the mechanical properties of large distribution transformers. Associated mechanical properties such as volumetric operations are also discussed

Use of proofs-as-programs to build an anology-based functional program editor

This thesis presents a novel application of the technique known as proofs-as-programs. Proofs-as-programs defines a correspondence between proofs in a constructive logic and functional programs. By using this correspondence, a functional program may be represented directly as the proof of a specification and so the program may be analysed within this proof framework. CʸNTHIA is a program editor for the functional language ML which uses proofs-as-programs to analyse users' programs as they are written. So that the user requires no knowledge of proof theory, the underlying proof representation is completely hidden. The proof framework allows programs written in CʸNTHIA to be checked to be syntactically correct, well-typed, well-defined and terminating. CʸNTHIA also embodies the idea of programming by analogy — rather than starting from scratch, users always begin with an existing function definition. They then apply a sequence of high-level editing commands which transform this starting definition into the one required. These commands preserve correctness and also increase programming efficiency by automating commonly occurring steps. The design and implementation of CʸNTHIA is described and its role as a novice programming environment is investigated. Use by experts is possible but only a sub-set of ML is currently supported. Two major trials of CʸNTHIA have shown that CʸNTHIA is well-suited as a teaching tool. Users of CʸNTHIA make fewer programming errors and the feedback facilities of CʸNTHIA mean that it is easier to track down the source of errors when they do occur

Tools and Algorithms for the Construction and Analysis of Systems

This open access book constitutes the proceedings of the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2022, which was held during April 2-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 46 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 159 submissions. The proceedings also contain 16 tool papers of the affiliated competition SV-Comp and 1 paper consisting of the competition report. TACAS is a forum for researchers, developers, and users interested in rigorously based tools and algorithms for the construction and analysis of systems. The conference aims to bridge the gaps between different communities with this common interest and to support them in their quest to improve the utility, reliability, exibility, and efficiency of tools and algorithms for building computer-controlled systems