Anchor: Packet switching is a frugal, efficient way to send data from point a to point b (albeit via points c, d, q, and k).
Entailed: Packet switching is cheap and sends data quickly.
Contradiction: Packet switching is expensive and takes a long time to send data.
Contradiction: There are none. 
Contradiction: Two guys looking at a tire.
Contradiction: A dog is walking on a street.
Contradiction: There are people.