Part II Structures242
lationships, such as being in conflict, being compatible, being independent, being
capable of running in parallel. Planar Graphs—simple graphs that can be drawn in
the plane—are examined in Chapter 12, the final chapter of Part II. The impossi-
bility of placing 50 geocentric satellites in orbit so that theyuniformlyblanket the
globe will be one of the conclusions reached in this chapter.