Premise: "A white dog is trying to catch a ball in midair over a grassy field."\nHypothesis: "The dog is chasing a ball that someone threw."\nDo we know that the hypothesis entailed by the premise? A step-by-step solution is:

User
A dog trying to catch a ball doesn't necessarily imply someone threw the ball.
The final answer: it is not possible to tell.
Assistant