Removing Anti-Parallel Edges
We can't just subtract 4 from 10 to get 6 because the resulting
graph would not model the possiblity that we choose to use only the
pipe from v2 to v1.
Nodari Sitchinava (based on material by Dan Suthers)
Last modified: Sat Apr 12 14:00:58 HST 2014
Images are from the instructor's material for Cormen et al. Introduction to Algorithms, Third