On the behaviours produced by instruction sequences under execution

The behaviour produced by an instruction sequence under execution is a behaviour to be controlled by some execution environment: each step performed actuates the processing of an instruction by the execution environment and a reply returned at completion of the processing determines how the behaviour proceeds. The increasingly occurring case where the processing takes place remotely involves the generation of a stream of instructions to be processed and a remote execution unit that handles the processing of this stream of instructions. We use process algebra to describe the behaviours produced by instruction sequences under execution and to describe two protocols implementing these behaviours in the case of remote processing. We also show that all finite-state behaviours considered in process algebra can be produced by instruction sequences under execution