A SEMANTIC CHARACTERIZATION FOR FAULTS IN REPLICATED SYSTEMS

We describe a process algebraic approach to the semantics of replicate d systems. We extend a subset of CCS with a replication operator to mo del systems with replicated synchronous majority voting. Based on an o perational semantics, we define a bisimulation semantics. As the bisim ulation semantics does not characterise fault tolerance we define preo rders, which introduces a hierarchy of faulty processes and fault-tole rant processes. We then show how a similar ordering on modal-mu formul ae can characterise the fault preorders.