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Abstract. We propose a typing theory, based on multiparty session types, for modular verification of real-time choreographic interactions. To model real-time implementations, we introduce a simple calculus with delays and a decidable static proof system. The proof system with time constraints ensures type safety and time-error freedom, namely processes respect the prescribed timing and causalities between interactions. A decidable condition, enforceable on timed global types, guarantees global time-progress for validated processes with delays, and gives a sound and complete characterisation of a new class of CTAs with general topologies that enjoys global progress and liveness.

Abstract. We study long-running transactions in open componentbased distributed applications, such as Web Services platforms. Longrunning transactions describe time-extensive activities that involve several distributed components. Henceforth, in case of failure, it is usually not possible to restore the initial state, and firing a compensation process is preferable. Despite the interest of such transactional mechanisms, a formal modeling of them is still lacking. In this paper we address this issue by designing an extension of the asynchronous π-calculus with longrunning transactions (and sequences) -the πt-calculus. We study the practice of πt-calculus, by discussing few paradigmatic examples, and its theory, by defining a semantics and providing a correct encoding of πt-calculus into asynchronous π-calculus.

In large-scale distributed infrastructures, applications are realised through com- munications among distributed components. The need for methods for assuring safe interactions in such environments is recognised, however the existing frame- works, relying on centralised verification or restricted specification methods, have limited applicability. This paper proposes a new theory of monitored π -calculus with dynamic usage of multiparty session types (MPST), offering a rigorous foun- dation for safety assurance of distributed components which asynchronously com- municate through multiparty sessions. Our theory establishes a framework for semantically precise decentralised run-time enforcement and provides reasoning principles over monitored distributed applications, which complement existing static analysis techniques. We introduce asynchrony through the means of explicit routers and global queues, and propose novel equivalences between networks, that capture the notion of interface equivalence, i.e. equating networks offering the same services to a user. We illustrate our static-dynamic analysis system with an ATM protocol as a running example and justify our theory with results: satisfac- tion equivalence, local/global safety and transparency, and session fidelity

Abstract. We report on a formal framework being developed within the SEN-SORIA project for supporting service-oriented modelling at high levels of abstraction, i.e. independently of the hosting middleware and hardware platforms, and the languages in which services are programmed. More specifically, we give an account of the concepts and techniques that support the composition model of SENSORIA, i.e. the mechanisms through which complex applications can be put together from simpler components, including modelling primitives for the orchestration of components and the definition of external interfaces.