Programs from Chapter 6 include:

o bipartite_matching1.p	This is Program 6.1, p. 350-351
o bipartite_matching2.p	This is Program 6.2, p. 356-358
o general_matching.p	This is Program 6.3, p. 372-376
o net_decls.p		This is Program 6.4, p. 392
o dinic.p		This is Program 6.5, p. 393-395
o gravity.p		This is Program 6.6, p. 406-407
