Using higher-order contracts to model session types. (Extended Abstract)

Session types are used to describe and structure interactions between independent processes in distributed systems. Higher-order types are needed in order to properly structure delegation of responsibility between processes. In this paper we show that higher-order web-service contracts can be used to provide a fully-abstract model of recursive higher-order session types. The model is settheoretic, in the sense that the denotation of a contract is given by the set of contracts with which it complies; we use a novel notion of peer compliance. A crucial step in the proof of full-abstraction is showing that every contract has a non-empty denotation.