The files in this directory represent the case studies in Chapter 4, except that
swp.csp is the Sliding Window Protocol, not itself described in the book, is
an extended version of the Alternating Bit Protocol.  Aside from sudoku.csp,
abp.csp and swp.csp, all the .csp files relate to the section on  routing.

Virtual routing (the "Mad Postman") can be found in the directory for Chapter 8,
where it provides an interesting example of compression.

Several of the files use hiding, not introduced till Chapter 5.

Several of these examples reappear in modified form in later chapters.

