Raymond McDowell

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In order to reason about specifications of computations that are given via the proof search or logic programming paradigm one needs to have at least some forms of induction and some principle for reasoning about the ways in which terms are built and the ways in which computations can progress. The literature contains many approaches to formally adding these(More)
Logical frameworks based on intuitionistic or linear logics with higher-type quantification have been successfully used to give high-level, modular, and formal specifications of many important judgments in the area of programming languages and inference systems. Given such specifications, it is natural to consider proving properties about the specified(More)
Intuitionistic and linear logics can be used to specify the operational semantics of transition systems in various ways. We consider here two encodings: one uses linear logic and maps states of the transition system into formulas, and the other uses intuitionistic logic and maps states into terms. In both cases, it is possible to relate transition paths to(More)
Linear logic has been used to specify the operational semantics of various process calculi. In this paper we explore how meta-level judgments, such as simulation and bisimulation, can be established using such encodings. In general, linear logic is too weak to derive such judgments and we focus on an extension to linear logic using definitions. We explore(More)
1 Abstract We investigate extensions to the language of hereditary Harrop formulas as logical frameworks for meta-theoretic analysis of deductive systems. We nd that a combination of partial inductive dee-nitions and elementary number theory greatly increase our ability to express and analyze relations and their properties in a formal setting. We also(More)
We present a probabilistic model checking approach for evaluating the safety and operational suitability of the Airborne Collision Avoidance System X (ACAS X). This system issues advisories to pilots when the risk of mid-air collision is imminent, and is expected to be equipped on all large, piloted aircraft in the future. We developed an approach to(More)
It is recognised that business-to-business relationships involve individuals interacting over time. For companies whose relationships are a source of concern (they may perceive that they could enable a greater competitive advantage to be leveraged, or may consider that they are the reasons for poor performance), any attempts to manage their relationships(More)
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