Relating maximality-based semantics to action refinement in process algebras

This paper extends to process algebras the notion of maximality which has initially been introduced for prime event structures and P/T nets and shows how this notion of maximality may be used for deening an adequate semantics of Basic LOTOS able to support action reenement. Such an approach appears to be more convenient than the classical ST-semantics where non atomic actions are split into start and end sub-actions, as it makes it possible to escape from the potential state space explosion problems induced by action splitting. Main contributions of the paper are related to the deenition of a maximality-based operational semantics of LOTOS and to the expression of maximality-based bisimulation equivalences which are shown to be preserved under action reenement.