premise: A pro-baseball pitcher sends a curve ball to his opponent while many fans relax and enjoy the game. hypothesis: A pitcher is playing baseball.
entailment: A pro-baseball pitcher is also a pitcher and his sending a curve ball is part of the description of playing baseball.|entailment: A pro-baseball pitcher throws a curve ball, and this action is usually toward an opponent.|entailment: The pitcher is mentioned in both sentences. The first sentence states the pitcher is pro-baseball and sends a curve ball, so it's implied he is playing baseball.