Anchor: Now Shepard is quite right that if true productivity growth is 2 percent, not the 1-percent measured rate, and if the labor force is growing at 1 percent, then the economy's true speed limit is 3 percent, not 2 percent.
Entailed: The economy's speed limit depends on labor force growth.
Contradiction: The economy's speed limit is always below 1 percent.
Contradiction: A man is sleeping.
Contradiction: King's Cross, ordered Tuppence.
Contradiction: He was very frumpy in his dress. 
Contradiction: People are at school.