Refinement of actions in event structures and causal trees (Q688717)

Action refinement is studied in two closely related true concurrency models, namely \(\Delta\)-free event structures and causal trees. The former is a slight modification of prime event structures (obtained via weakening conflict heredity and relaxing the finite causes principle). Refinement amounts to events expansion and is compatible with the history-preserving equivalence. Causal trees are obtained as event structures factored by the history- preserving equivalence. Dynamic refinement operations are introduced and they are shown to be compatible with those of static refinement on \(\Delta\)-free event structures. It is suggested that causal trees can be used to construct a semantic calculus for process algebras enriched with refinement.