Abstract

Abstract. This paper presents the modal interface theory, a unification of interface automata and modal specifications, two radically dissimilar models for interface theories. Interface automata is a game-based model, which allows to make assumptions on the environment and propose an optimistic view for composition : two components can be composed if there is an environment where they can work together. Modal specification is a language theoretic account of a fragment of the modal mu-calculus logic with a rich composition algebra meeting some methodological requirements but which does not allow to distinguish between the environment and the component. The present paper contributes a thorougher unification of the two theories by correcting a first attempt in this direction by Larsen et al., drawing a complete picture of the modal interface algebra, and pushing even further the comparison between interface automata, modal automata and modal interfaces. The work reported here is based on the earlier work in