Atomicity Decomposition Sample Clauses

Atomicity Decomposition. In atomicity decomposition [RD8], coarse-grained atomicity is refined to more fine-grained atomicity. New events introduced in a refinement step are viewed as hidden events not visible to the environment of a system and are thus outside the control of the environment. Any number of executions of an internal action may occur in between each execution of a visible action. Model Decomposition The notion of model decomposition [RD8] covers machine and context decomposition. The entry point for the decomposition of a model is a machine and its whole hierarchy of seen contexts. The resulting sub-models are independent of each other, and the partition of the models includes the allocation of variables, invariants, events and even context elements like sets, constants and axioms to subparts. Model decomposition has two main styles. In shared variable style, events are partitioned into sub-components in different machines, variables associated with the original events get shared by the machines, and the sub-components can be refined independently but only in such a way that shared variables are present and not data-refined. In shared event style, variables are partitioned into sub-components in different machines, events associated with the variables get split accordingly, and the sub-components can be refined independently without constraints. Experience at University of Southampton University of Southampton maintains a decomposition plug-in [RD7] and, as documented in [RD8], has used the plug-in for applying the above-described decompositional approaches to BepiColombo SIXS/MIXS OBSW. SSF’s non-decompositional Event-B projects have been used as de facto primary specifications in this experiment that has turned out useful in development of decompositional practices. SSF has no relevant experience about the decomposition plug-in but sees the above-described approaches being motivated by a several decades long history of process-algebraic approaches.

Atomicity Decomposition. In atomicity decomposition [RD9], coarse-­‐grained atomicity is refined to more fine-­‐ grained atomicity. New events introduced in a refinement step are viewed as hidden events not visible to the environment of a system and are thus outside the control of the environment. Any number of executions of an internal action may occur in between each execution of a visible action.