This paper publicly reveals, motivates, and surveys the results of an ambitious hidden agenda for applying algebra to software engineering. The paper reviews selected literature, introduces a new perspective on nondeterminism, and features powerful hidden coinduction techniques for proving behavioral properties of concurrent systems, especially renements; some proofs are given using OBJ3. We also discuss where modularization, bisimulation, transition systems and combinations of the object, logic, constraint and functional paradigms t into our hidden agenda. 1 Introduction Algebra can be useful in many dierent ways in software engineering, including specication, validation, language design, and underlying theory. Specication and validation can help in the practical production of reliable programs, advances in language design can help improve the state of the art, and theory can help with building new tools to increase automation, as well as with showing correctness of the whole e...

This paper surveys and evaluates some techniques for eliciting requirements of computer-based systems, paying particular attention to how they deal with social issues. The methods surveyed include introspection, interviews, questionnaires, and protocol, conversation, interaction, and discourse analyses. Although they are relatively untried in Requirements Engineering, we believe there is much promise in the last three techniques, which grew out of ethnomethodology and sociolinguistics. In particular, they can elicit tacit knowledge by observing actual interactions in the workplace, and can also be applied to the system development process itself.

This paper describes an approach to module composition by executing "module expressions" to build systems out of component modules; the paper also gives a novel semantics intended to aid implementers. The semantics is based on set theoretic notions of tuple set, partial signature, and institution, thus avoiding more difficult mathematics theory. Language features include information hiding, both vertical and horizontal composition, and views for binding modules to interfaces. Vertical composition refers to the hierarchical structuring of a system into layers, while horizontal composition refers to the structure of a given layer. Modules may involve information hiding, and views may involve behavioral satisfaction of a theory by a module. Several "Laws of Software Composition" are given, which show how the various module composition operations relate. Taken together, this gives foundations for an algebraic approach to software engineering. 1.1 Introduction The approach to module compos...

This paper unveils and motivates an ambitious programme of hidden algebraic research in software engineering, beginning with our general goals, continuing with an overview of results, and including some future plans. The main contribution is powerful hidden coinduction techniques for proving behavioral correctness of concurrent systems; several mechanical proofs are given using OBJ3. We also show how modularization, bisimulation, transition systems, concurrency and combinations of the functional, constraint, logic and object paradigms fit into hidden algebra. 1. Introduction

: This paper is an introduction to recent research on hidden algebra and its application to software engineering; it is intended to be informal and friendly, but still precise. We first review classical algebraic specification for traditional "Platonic" abstract data types like integers, vectors, matrices, and lists. Software engineering also needs changeable "abstract machines," recently called "objects," that can communicate concurrently with other objects through visible "attributes" and state-changing "methods." Hidden algebra is a new development in algebraic semantics designed to handle such systems. Equational theories are used in both cases, but the notion of satisfaction for hidden algebra is behavioral, in the sense that equations need only appear to be true under all possible experiments; this extra flexibility is needed to accommodate the clever implementations that software engineers often use to conserve space and/or time. The most important results in hidden algebra are ...

: This paper outlines a research programme in algebraic engineering. It starts with a review of classical algebraic specification for abstract data types, such as integers, vectors, booleans, and lists. Software engineering also needs abstract machines, recently called "objects," that can communicate concurrently with other objects, and that have local states with visible "attributes" that are changed by inputs. Hidden algebra is a new development in algebraic semantics for such systems; its most important results are powerful hidden coinduction principles for proving behavioral properties, especially behavioral refinement. 1 Introduction In view of the title of this conference, I should confess to being an algebraic engineer in (perhaps) the following four different senses: 1. I use algebra to build real software systems. 2. I build huge algebras to help build software systems. 3. I build software tools to help deal with these huge algebras. 4. I build new kinds of algebra, to get be...

This paper surveys and evaluates some techniques for eliciting requirements of computer-based systems, paying particular attention to how they deal with social issues. The methods surveyed include introspection, interviews, questionnaires, and protocol, conversation, interaction, and discourse analyses. Although they are relatively untried in Requirements Engineering, we believe there is much promise in the last three techniques, which grew out of ethnomethodology and sociolinguistics. In particular, they can elicit tacit knowledge by observing actual interactions in the workplace, and can also be applied to the system development process itself.