Model-theoretic Approaches to Semantic Integration (Extended Abstract)

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Tools for producing formal specifications : a view of current architectures and future directions

During the last decade, one important contribution towards requirements engineering has been the advent of formal specification languages. They offer a well-defined notation that can improve consistency and avoid ambiguity in specifications. However, the process of obtaining formal specifications that are consistent with the requirements is itself a difficult activity. Hence various researchers are developing systems that aid the transition from informal to formal specifications. The kind of problems tackled and the contributions made by these proposed systems are very diverse. This paper brings these studies together to provide a vision for future architectures that aim to aid the transition from informal to formal specifications. The new architecture, which is based on the strengths of existing studies, tackles a number of key issues in requirements engineering such as identifying ambiguities, incompleteness, and reusability. The paper concludes with a discussion of the research problems that need to be addressed in order to realise the proposed architecture

Suszko's Problem: Mixed Consequence and Compositionality

Suszko's problem is the problem of finding the minimal number of truth values needed to semantically characterize a syntactic consequence relation. Suszko proved that every Tarskian consequence relation can be characterized using only two truth values. Malinowski showed that this number can equal three if some of Tarski's structural constraints are relaxed. By so doing, Malinowski introduced a case of so-called mixed consequence, allowing the notion of a designated value to vary between the premises and the conclusions of an argument. In this paper we give a more systematic perspective on Suszko's problem and on mixed consequence. First, we prove general representation theorems relating structural properties of a consequence relation to their semantic interpretation, uncovering the semantic counterpart of substitution-invariance, and establishing that (intersective) mixed consequence is fundamentally the semantic counterpart of the structural property of monotonicity. We use those to derive maximum-rank results proved recently in a different setting by French and Ripley, as well as by Blasio, Marcos and Wansing, for logics with various structural properties (reflexivity, transitivity, none, or both). We strengthen these results into exact rank results for non-permeable logics (roughly, those which distinguish the role of premises and conclusions). We discuss the underlying notion of rank, and the associated reduction proposed independently by Scott and Suszko. As emphasized by Suszko, that reduction fails to preserve compositionality in general, meaning that the resulting semantics is no longer truth-functional. We propose a modification of that notion of reduction, allowing us to prove that over compact logics with what we call regular connectives, rank results are maintained even if we request the preservation of truth-functionality and additional semantic properties.Comment: Keywords: Suszko's thesis; truth value; logical consequence; mixed consequence; compositionality; truth-functionality; many-valued logic; algebraic logic; substructural logics; regular connective

A Design for verification approach using an embedding of PSL in AsmL

In this paper, we propose to integrate an embedding of Property Specification Language (PSL) in Abstract State Machines Language (AsmL) with a top–down design for verification approach in order to enable the model checking of large systems at the early stages of the design process. We provide a complete embedding of PSL in the ASM language AsmL, which allows us to integrate PSL properties as a part of the design. For verification, we propose a technique based on the AsmL tool that translates the code containing both the design and the properties into a finite state machine (FSM) representation. We use the generated FSM to run model checking on an external tool, here SMV. Our approach takes advantage of the AsmL language capabilities to model designs at the system level as well as from the power of the AsmL tool in generating both C# code and FSMs from AsmL models. We applied our approach on the PCI-X bus standard, which AsmL model was constructed from the informal standard specifications and a subsequent UML model. Experimental results on the PCI-X bus case study showed a superiority of our approach to conventional verification

Requirements, design and business process reengineering as vital parts of any system development methodology

This thesis analyzes different aspects of system development life cycle, concentrating on the requirements and design stages. It describes various methodologies, methods and tools that have been developed over the years. It evaluates them and compares them against each other. Finally a conclusion is made that there is a very important stage missing in the system development life cycle, which is the Business Process Reengineering Stage