We introduce a calculus describing the movement of processes and devices, including movement through administrative domains.
Outline ¥ Topic of this tutorial: a foundation for object-oriented languages based on object calculi. ¥ The mainstream. ¥ We review only common, kernel properties.
Our objective is to understand the notion of <I>type</I> in programming languages, present a model of typed, polymorphic programming languages that reflects recent research in type theory, and examine the relevance of recent research to the design of practical programming languages. Object-oriented languages provide both a framework and a motivation for… (More)
The Ambient Calculus is a process calculus where processes may reside within a hierarchy of locations and modify it. The purpose of the calculus is to study mobility, which is seen as the change of spatial configurations over time. In order to describe properties of mobile computations we devise a modal logic that can talk about space as well as time, and… (More)
Obliq is a lexically-scoped, untyped, interpreted language that supports distributed object-oriented computation. Obliq objects have state and are local to a site. Obliq computations can roam over the network, while maintaining network connections. Distributed lexical scoping is the key mechanism for managing distributed computation.
We investigate the interactions of subtyping and recursive types, in a simply typed λ-calculus. The two fundamental questions here are whether two (recursive)types are in the subtype relation and whether a term has a type. To address the first question, we relate various definitions of type equivalence and subtyping that are induced by a model, an… (More)
Java has demonstrated the utility of type systems for mobile code, and in particular their use and implications for security. Security properties rest on the fact that a well-typed Java program (or the corresponding verified bytecode) cannot cause certain kinds of damage.In this paper we provide a type system for mobile computation, that is, for computation… (More)
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The λ&sgr;-calculus is a refinement of the λ-calculus where substitutions are manipulated explicitly. The λ&sgr;-calculus provides a setting for studying the theory of substitutions, with pleasant mathematical properties. It is also a useful bridge between the classical λ-calculus and concrete implementations.