Abstract:
In "Logic and the Flow of Information" (1997), Jon Barwise and I set out to provide an algebraic theory of information flow based on, but abstracted from, situation theory. In it, the core concept is that of an "infomorphism", which itself is a generalisation of the notion of a continuous function in topology and has been much used in computer science for the semantics of programming languages and as a foundational model of processes. (In that field it is known as the morphism of a Chu space.) In this talk, I will compare ideas from dynamic modal logic, such as public and private announcement, aiming at an "infomorphic" characterisation. This is work in progress.