This chapter has introduced the facilities that have been added to SETL for network communication. The liberal use of processes can be seen to be playing a role in the design methodology for handling various functional concerns that arise in the small but canonical example of the line-length server. Select has started to emerge as the central event-awaiting routine of servers and other processes that must be responsive at all times to nondeterministically arriving inputs.
In the next chapter, these themes are explored further in a larger server case study.