A Refinement Calculus for Logic Programs

Existing refinement calculi provide frameworks for the stepwise development of imperative programs from specifications. This paper presents a refinement calculus for deriving logic programs. The calculus contains a wide-spectrum logic programming language, including executable constructs such as sequential conjunction, disjunction, and existential quantification, as well as specification constructs such as general predicates, assumptions and universal quantification. A declarative semantics is defined for this wide-spectrum language based on executions. Executions are partial functions from states to states, where a state is represented as a set of bindings. The semantics is used to define the meaning of programs and specifications, including parameters and recursion. To complete the calculus, a notion of correctness-preserving refinement over programs in the wide-spectrum language is defined and refinement laws for developing programs are introduced. The refinement calculus is illustrated using example derivations and prototype tool support is discussed.Comment: 36 pages, 3 figures. To be published in Theory and Practice of Logic Programming (TPLP

Coinductive Formal Reasoning in Exact Real Arithmetic

In this article we present a method for formally proving the correctness of the lazy algorithms for computing homographic and quadratic transformations -- of which field operations are special cases-- on a representation of real numbers by coinductive streams. The algorithms work on coinductive stream of M\"{o}bius maps and form the basis of the Edalat--Potts exact real arithmetic. We use the machinery of the Coq proof assistant for the coinductive types to present the formalisation. The formalised algorithms are only partially productive, i.e., they do not output provably infinite streams for all possible inputs. We show how to deal with this partiality in the presence of syntactic restrictions posed by the constructive type theory of Coq. Furthermore we show that the type theoretic techniques that we develop are compatible with the semantics of the algorithms as continuous maps on real numbers. The resulting Coq formalisation is available for public download.Comment: 40 page

Using Event Calculus to Formalise Policy Specification and Analysis

As the interest in using policy-based approaches for systems management grows, it is becoming increasingly important to develop methods for performing analysis and refinement of policy specifications. Although this is an area that researchers have devoted some attention to, none of the proposed solutions address the issues of analysing specifications that combine authorisation and management policies; analysing policy specifications that contain constraints on the applicability of the policies; and performing a priori analysis of the specification that will both detect the presence of inconsistencies and explain the situations in which the conflict will occur. We present a method for transforming both policy and system behaviour specifications into a formal notation that is based on event calculus. Additionally it describes how this formalism can be used in conjunction with abductive reasoning techniques to perform a priori analysis of policy specifications for the various conflict types identified in the literature. Finally, it presents some initial thoughts on how this notation and analysis technique could be used to perform policy refinement

Abstract State Machines 1988-1998: Commented ASM Bibliography

An annotated bibliography of papers which deal with or use Abstract State Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm

Logic Models....Not Just for Big Foundations Anymore

Logic modeling is popular with large foundations, but has not been embraced by many of the smaller ones. One reason is that foundations with few or no staff fear that producing one is complicated and time consuming. It doesn't have to be. And it can be a crucial tool for small asset foundations looking to make sustained impact.This report offers a case study of how the KDK-Harman Foundation created a logic model laying out its underlying assumptions and theories of change and aligning goals, activities, and intended outcomes and how it incorporated the model into decision-making processes

A Good Idea is Not Enough: Understanding the Challenges of Entrepreneurship Communication

This paper addresses a less-investigated issue of innovations: entrepreneurship communication. Business and marketing studies demonstrate that new product development processes do not succeed on good technical invention alone. To succeed, the invention must be appropriately communicated to a market and iterated through dialogue with potential stakeholders. We explore this issue by examining communication-related challenges, abilities and barriers from the perspectives of innovators trying to enter an unfamiliar, foreign market. Specifically, we summarize results of a set of studies conducted in the Gyeonggi Innovation Program (GIP), an entrepreneurship program formed by a partnership between the University of Texas at Austin and Gyeonggi-Do Province in South Korea. Through the GIP, Korean entrepreneurs attempt to expand domestically successful product ideas to the American market. The study results demonstrate that these innovators must deal with a broad range of challenges, particularly (1) developing deeper understanding of market needs, values, and cultural expectations, and (2) producing pitches with the structure, claims and evidence, and engagement strategies expected by American stakeholders. These studies confirm that a deeper understanding of successful new product development (NPD) projects requires not only a culturally authentic NPD process model, but also communication-oriented research. The GIP approach offers insights into good programmatic concept and effective methods for training engineers to become entrepreneurs. Yet we also identify potential improvements for such programs. Finally, we draw implications for studying entrepreneurship communication.IC2 Institut

Towards correct-by-construction product variants of a software product line: GFML, a formal language for feature modules

Software Product Line Engineering (SPLE) is a software engineering paradigm that focuses on reuse and variability. Although feature-oriented programming (FOP) can implement software product line efficiently, we still need a method to generate and prove correctness of all product variants more efficiently and automatically. In this context, we propose to manipulate feature modules which contain three kinds of artifacts: specification, code and correctness proof. We depict a methodology and a platform that help the user to automatically produce correct-by-construction product variants from the related feature modules. As a first step of this project, we begin by proposing a language, GFML, allowing the developer to write such feature modules. This language is designed so that the artifacts can be easily reused and composed. GFML files contain the different artifacts mentioned above.The idea is to compile them into FoCaLiZe, a language for specification, implementation and formal proof with some object-oriented flavor. In this paper, we define and illustrate this language. We also introduce a way to compose the feature modules on some examples.Comment: In Proceedings FMSPLE 2015, arXiv:1504.0301