Drossopoulou and Noble [6] argue persuasively for the need for a means to express policy in object-capabilitybased systems. We investigate a practical means to realize their aim via the Curry-Howard isomorphism [1] [13]. Specifically, we investigate representing policy as types in a behavioral type system for the rho-calculus [15], a reflective higher-order variant of the π-calculus [18].

There are many notions of type in computing. The most classical notion is \types as sets", which has been extended to cover many features of modern programming languages. This paper shows that such features are handled perhaps even more naturally by an extension of the \types as algebras" notion to a \types as theories" notion. This notion naturally supports object oriented concepts, including ...

— This paper présents a simplified construction of an algorithm space. The intuitive notion ofan algorithm collection goes back to Nolin 1974. Our goal is her e to formalize and simplify this présentation of algorithm theory. The introduction of a computability notion was induced by the utilization of bundie theory. We build an enumerable algorithm space where ever y object is computable. Résum...

In this paper we present a new approach to the semantics of data types, in which the types themselves are incorporated as elements of the domain of data objects. The approach allows types to have subtypes, allows genuinely polymorphic functions, and gives a precise semantics for recursive type definitions (including definitions with parameters). In addition, the approach yields simple and strai...

When modern type theories are employed for formal semantics, common nouns (CNs) are interpreted as types, not as predicates. Although this brings about some technical advantages, it is worthwhile to ask: what is special about CNs that merits them to be interpreted as types? We discuss the observation made by Geach that, unlike other lexical categories, CNs have criteria of identity, a component...

This paper argues that there is an important role to be played by questions in logic, both semantically and proof-theoretically. Semantically, we show that, by generalizing the classical notion of entailment to questions, we can capture not only the standard relation of logical consequence, which concerns specific pieces of information, but also the relation of logical dependency, which concern...