Abstract

Intensional logic is the mathematical foundation for Intensional Programming Languages (IPL). Lucid, initially founded on the dataflow paradigm, embraced intensional logic, and became a multi-dimensional intensional programming language. In all these developments context was the core concept. In its becoming an IPL, Lucid implicitly absorbed the notion of context, allowing expressions to be evaluated at different contexts. However, context cannot be explicitly named and manipulated in the current versions of Lucid. This restricts the ability of Lucid to be an effective programming language for programming diverse applications. This thesis discusses the extension of Lucid with contexts as a first class object. That is, contexts can be defined, assigned values, used in expressions, and passed as function parameters. The language thus extended, is called Lucx ( Lu cid extended with c[barbelow]ontex[barbelow]ts )(the x is used as the x in Latex). A context theory is developed to provide a semantic basis for context manipulation in Lucx. That is, contexts, context operators, and a context calculus are formally defined, and the formal syntax and semantics of Lucx are also given. The benefits achieved by such an extension are illustrated by applying the extended language to program different applications including Timed Systems, Agent Communication, Constraint Programming, and in the formal development of context-aware systems.