. We present a general semantic universe of call-by-value computation based on elements of game semantics, and validate its appropriateness as a semantic universe by the full abstraction result for call-by-value PCF, a generic typed programming language with call-by-value evaluation. The key idea is to consider the distinction between call-by-name and call-by-value as that of the structure of information flow, which determines the basic form of games. In this way the call-by-name computation and call-by-value computation arise as two independent instances of sequential functional computation with distinct algebraic structures. We elucidate the type structures of the universe following the standard categorical framework developed in the context of domain theory. Mutual relationship between the presented category of games and the corresponding call-by-name universe is also clarified. 1. Introduction The call-by-value is a mode of calling procedures widely used in imperative and function...

. We present a general theory of behavioural subtyping for name passing interactive behaviours using early name-passing synchronisation trees. In this theory types are collections of name passing synchronisation trees organised by typed variants of processtheoretic operations, and a simple behavioural notion of subtyping specifies when one type denotes more constrained behaviours than another, offering a semantic basis for diverse instances of subtyping in sequential and concurrent computation through their representation in name passing. The robustness of the notion is shown by a few equivalent characterisations, including the one based on the subset inclusion with respect to inhabitants of types and another concerning a basic substitutability property. As an application, we show how the subtyping in the -calculus with constant data domains is soundly embeddable into the present theory, illuminating the functional notion of subtyping from a behavioural viewpoint. 1. Introduction The ...

We introduce a theory of behavioural types as a semantic foundation of typed ß-calculi. In this theory, a type is a set of behaviours, represented by early name passing synchronisation trees, which conform to a certain behavioural constraint. Operations on typed processes are derived from typed variants of well-known process-theoretic operations for mobile processes, and each model of typed ß-calculi in a typed universe induces a compositional theory of typed bisimilarities. The construction is simple and intuitive, yet offers a rich class of typed universes of name passing interactive behaviours, which contain, among others, models of known typed ß-calculi and universes of game semantics. As a simple but non-trivial application, we show how the sorting by Milner can be given a sound model in a basic universe of types. The soundness states not only that the interpretation is sound in the standard sense, but also that the untyped interactive behaviour of typed terms is justifiable on t...