Anchor: If the Postal Service were about 13 percent inefficient, there would be zero net scale benefit.
Entailed: The postal service won't have any net scale benefit if and when they are around, two numbers short of, 15 percent inefficient. 
Contradiction: At 13 percent inefficiency, the postal service has 100 percent net scale benefit. 
Contradiction: The man is watching TV.
Contradiction: Our nation does a lot of unnecessary things that the soviets did too.
Contradiction: I carelessly ran as fast as I could
Contradiction: There are animals in the grass