Section: Scientific Foundations

Type systems and logics

Type systems and logics for reasoning on computations are among the most successful outcomes in the history of the research in $\lambda$-calculus and (more recently) in process calculi. Type systems can also represent a powerful means of specifying dialogues among components of CBUS. For instance—again referring to Web services—current languages for specifying interactions only express basic connectivity, ignoring causality and timing aspects (e.g., an intended order on the messages), and the alternative is to use Turing Complete languages that are however undecidable. Types can come at hand here: they can express causality and order information on messages [58] , [56] , [59] , while remaining decidable systems.