Anchor: Arm-strokes from swimmers who are racing in the pool.
Entailed: Swimmers are competing in the pool.
Contradiction: No one is in the water.
Contradiction: NASA has nothing to do with the Polar Lander.
Contradiction: Price Elasticity of Demand is equivalent to a one percent increase in the price of the good.  
Contradiction: Tuppence has never correctly judged a situation in her life. 
Contradiction: People wait to cross a street.