A pi-calculus Process Semantics of Concurrent Idealised ALGOL

We study the use of the-calculus for semantical descriptions of languages such as Concurrent Idealised ALGOL (CIA), combining imperative, functional and concurrent features. We rst present an operational semantics for CIA, given by SOS rules and a contextual form of behavioural equivalence; then a-calculus semantics. As behavioural equivalence on-calculus processes we choose the standard (weak early) bisimilarity. We compare the two semantics, demonstrating that there is a close operational correspondence between them and that the-calculus semantics is sound. This allows for applying the-calculus theory in proving behavioural properties of CIA phrases. We discuss laws and examples which have served as benchmarks to various semantics, and a more complex example involving procedures of higher order.