About fair asynchrony

AbstractThis paper examines the joint influence of fairness and asynchrony on the semantic modelling of a C.C.S.-like language. Fairness is the guarantee for every agent engaged in a computation to communicate with the other asynchronous agents if such communications are infinitely often possible. Programs are compared according to an implementation preorder which reflects the inclusion of observable properties: whenever, for every context |c and for every program r, no computation of r, experimenting upon |c (p) allows to recognize p versus q, p is considered less than q. A fully abstract model of the preorder is constructed in a domain of infinitary language, preferred here to classical algebraic domains. The restriction to bounded parallelism is analysed. In that simplified framework, the model turns effective and, moreover, decidable