From Verified Models to Verifiable Code

Declarative specifications of digital systems often contain parts that can be automatically translated into executable code. Automated code generation may reduce or eliminate the kinds of errors typically introduced through manual code writing. For this approach to be effective, the generated code should be reasonably efficient and, more importantly, verifiable. This paper presents a prototype code generator for the Prototype Verification System (PVS) that translates a subset of PVS functional specifications into an intermediate language and subsequently to multiple target programming languages. Several case studies are presented to illustrate the tool's functionality. The generated code can be analyzed by software verification tools such as verification condition generators, static analyzers, and software model-checkers to increase the confidence that the generated code is correct

Strategic Issues, Problems and Challenges in Inductive Theorem Proving

Abstract(Automated) Inductive Theorem Proving (ITP) is a challenging field in automated reasoning and theorem proving. Typically, (Automated) Theorem Proving (TP) refers to methods, techniques and tools for automatically proving general (most often first-order) theorems. Nowadays, the field of TP has reached a certain degree of maturity and powerful TP systems are widely available and used. The situation with ITP is strikingly different, in the sense that proving inductive theorems in an essentially automatic way still is a very challenging task, even for the most advanced existing ITP systems. Both in general TP and in ITP, strategies for guiding the proof search process are of fundamental importance, in automated as well as in interactive or mixed settings. In the paper we will analyze and discuss the most important strategic and proof search issues in ITP, compare ITP with TP, and argue why ITP is in a sense much more challenging. More generally, we will systematically isolate, investigate and classify the main problems and challenges in ITP w.r.t. automation, on different levels and from different points of views. Finally, based on this analysis we will present some theses about the state of the art in the field, possible criteria for what could be considered as substantial progress, and promising lines of research for the future, towards (more) automated ITP

FLAVERS: a Finite State Verification Technique for Software Systems

Software systems are increasing in size and complexity and, subsequently, are becoming ever more difficult to validate. Finite State Verification (FSV) has been gaining credibility and attention as an alternative to testing and to formal verification approaches based on theorem proving. There has recently been a great deal of excitement about the potential for FSV approaches to prove properties about hardware descriptions but, for the most part, these approaches do not scale adequately to handle the complexity usually found in software. In this paper, we describe an FSV approach that creates a compact and conservative, but imprecise, model of the system being analyzed, and then assists the analyst in adding additional details as guided by previous analysis results. This paper describes this approach and a prototype implementation, called FLAVERS, presents a detailed example, and then provides some experimental results demonstrating scalability

Colored model based testing for software product lines (CMBT-SWPL)

Over the last decade, the software product line domain has emerged as one of the mostpromising software development paradigms. The main benefits of a software product lineapproach are improvements in productivity, time to market, product quality, and customersatisfaction.Therefore, one topic that needs greater emphasis is testing of software product lines toachieve the required software quality assurance. Our concern is how to test a softwareproduct line as early as possible in order to detect errors, because the cost of error detectedIn early phases is much less compared to the cost of errors when detected later.The method suggested in this thesis is a model-based, reuse-oriented test technique calledColored Model Based Testing for Software Product Lines (CMBT-SWPL). CMBT-SWPLis a requirements-based approach for efficiently generating tests for products in a soft-ware product line. This testing approach is used for validation and verification of productlines. It is a novel approach to test product lines using a Colored State Chart (CSC), whichconsiders variability early in the product line development process. More precisely, the vari-ability will be introduced in the main components of the CSC. Accordingly, the variabilityis preserved in test cases, as they are generated from colored test models automatically.During domain engineering, the CSC is derived from the feature model. By coloring theState Chart, the behavior of several product line variants can be modeled simultaneouslyin a single diagram and thus address product line variability early. The CSC representsthe test model, from which test cases using statistical testing are derived.During application engineering, these colored test models are customized for a specificapplication of the product line. At the end of this test process, the test cases are generatedagain using statistical testing, executed and the test results are ready for evaluation. Inxaddition, the CSC will be transformed to a Colored Petri Net (CPN) for verification andsimulation purposes.The main gains of applying the CMBT-SWPL method are early detection of defects inrequirements, such as ambiguities incompleteness and redundancy which is then reflectedin saving the test effort, time, development and maintenance costs

New forms of collaborative innovation and production on the internet : an interdisciplinary perspective

Contents Introduction 1 New forms of collaborative innovation and production on the Internet : Volker Wittke and Heidemarie Hanekop Interdisciplinary perspectives on collaborative innovation and production: Conceptual debates 2 Customer Co-Creation: Open Innovation with Customers : Frank Piller, Christoph Ihl and Alexander Vossen 3 Governing Social Production : Niva Elkin-Koren 4 Trust Management in Online Communities : Audun Jøsang 5 Building a reputation system for Wikipedia : Christian Damsgaard Jensen 6 Cooperation in Wikipedia from a Network Perspective : Christian Stegbauer Firm driven collaborative innovation and production: Case studies 7 Managing a New Consumer Culture: “Working Consumers” in Web 2.0 as a Source of Corporate Feedback : Sabine Hornung, Frank Kleemann and G. Günter Voß 8 Prosuming, or when customers turn collaborators: coordination and motivation of customer contribution : Birgit Blättel-Mink, Raphael Menez, Dirk Dalichau, Daniel Kahnert 9 Role Confusion in Open Innovation Intermediary Arenas : Tobias Fredberg, Maria Elmquist, Susanne Ollila, Anna Yström List of Contributor

New forms of collaborative innovation and production on the internet

The Internet has enabled new forms of large-scale collaboration. Voluntary contributions by large numbers of users and co-producers lead to new forms of production and innovation, as seen in Wikipedia, open source software development, in social networks or on user-generated content platforms as well as in many firm-driven Web 2.0 services. Large-scale collaboration on the Internet is an intriguing phenomenon for scholarly debate because it challenges well established insights into the governance of economic action, the sources of innovation, the possibilities of collective action and the social, legal and technical preconditions for successful collaboration. Although contributions to the debate from various disciplines and fine-grained empirical studies already exist, there still is a lack of an interdisciplinary approach

New forms of collaborative innovation and production on the internet

The Internet has enabled new forms of large-scale collaboration. Voluntary contributions by large numbers of users and co-producers lead to new forms of production and innovation, as seen in Wikipedia, open source software development, in social networks or on user-generated content platforms as well as in many firm-driven Web 2.0 services. Large-scale collaboration on the Internet is an intriguing phenomenon for scholarly debate because it challenges well established insights into the governance of economic action, the sources of innovation, the possibilities of collective action and the social, legal and technical preconditions for successful collaboration. Although contributions to the debate from various disciplines and fine-grained empirical studies already exist, there still is a lack of an interdisciplinary approach

New forms of collaborative innovation and production on the internet - an interdisciplinary perspective

The Internet has enabled new forms of large-scale collaboration. Voluntary contributions by large numbers of users and co-producers lead to new forms of production and innovation, as seen in Wikipedia, open source software development, in social networks or on user-generated content platforms as well as in many firm-driven Web 2.0 services. Large-scale collaboration on the Internet is an intriguing phenomenon for scholarly debate because it challenges well established insights into the governance of economic action, the sources of innovation, the possibilities of collective action and the social, legal and technical preconditions for successful collaboration. Although contributions to the debate from various disciplines and fine-grained empirical studies already exist, there still is a lack of an interdisciplinary approach

Verification of floating point programs

In this thesis we present an approach to automated verification of floating point programs. Existing techniques for automated generation of correctness theorems are extended to produce proof obligations for accuracy guarantees and absence of floating point exceptions. A prototype automated real number theorem prover is presented, demonstrating a novel application of function interval arithmetic in the context of subdivision-based numerical theorem proving. The prototype is tested on correctness theorems for two simple yet nontrivial programs, proving exception freedom and tight accuracy guarantees automatically. The prover demonstrates a novel application of function interval arithmetic in the context of subdivision-based numerical theorem proving. The experiments show how function intervals can be used to combat the information loss problems that limit the applicability of traditional interval arithmetic in the context of hard real number theorem proving

Specifying a forest harvest scheduling system which includes wood properties.

M. Sc. University of KwaZulu-Natal, Durban 2009.This dissertation aims to specify a forest harvest scheduling system which includes wood properties in the harvesting decisions for the long-term (strategic) planning horizon. This system will be used by plantation forestry companies which supply wood to pulp manufacturers, who desire a more uniform raw material entering pulp mills so that a more uniform product results. Vertically integrated forestry companies would benefit particularly, as the allocation of timber to mills, as well as the timber transport costs, are included in the system. It has been found from literature that only one forest harvest scheduling system exists which includes wood properties in the harvesting decision; however, this system was a short-term (operational) system. To our knowledge, no other system which includes wood properties in the harvesting decision has been reported. As the forest harvest scheduling system is affected by the forest, transport, mill and forest planning domains, their procedures and constraints, these domains were described first, and the forest harvest scheduling system described next. The system and the environments (or domains) were specified with two techniques: semi-formal and formal methods. The semi-formal method used the Zachman framework to structure the specification. The Business owner’s view of the system was used. This framework uses complementary models such as entity-relationship diagrams, business process diagrams and state charts to describe aspects of the same thing. The formal method specification used the Z notation which is based on set theory and predicate logic. The semi-formal and formal specifications together form a complementary specification. The semi-formal specification is more understandable by clients, but could contain inconsistencies. The formal specification is more precise, but because it uses mathematical notation, is not as well understood. The semi-formal specification describes more features, while the formal specification describes the features in depth. The forest harvest scheduling system specified uses wood properties in the harvesting and timber allocation decisions over the strategic planning horizon. When the system is implemented, wood having more uniform properties will be delivered to the mill, ensuring a more uniform pulp product