Finite But Unbounded Delay In Synchronous CCS

We recast Milner's work on SCCS, a calculus for nite but unbounded delay based on SCCS, by giving a denotational semantics for admissibility of innnite computations on a biinite domain K. Using Abramsky's SFP domain D for bisimulation we obtain a fully abstract model in D K for an operational preorder which includes divergence and, if restricted to nite behaviour, corresponds to Abramsky's nitary preorder. We use nite but unbounded delay, choice and the synchronous product to derive a fair parallel operator in SCCS.