Global Types and Event Structure Semantics for Asynchronous Multiparty Sessions

We propose an interpretation of multiparty sessions with asynchronous communication as "Flow Event Structures". We introduce a new notion of "asynchronous type" for such sessions, ensuring the expected properties for multiparty sessions,including progress. Our asynchronous types, which reflect asynchrony more directly and more precisely than standard global types and are more permissive, are themselves interpreted as "Prime Event Structures". The main result is that the Event Structure interpretation of a session is equivalent, when the session is typable, to the Event Structure interpretation of its asynchronous type, namely their domains of configurations are isomorphic.