context: Guy in uniform standing on the side of a boat moving through the water.
hypothesis: We doubt that a man in the Navy stands on a boat in the cool air.
valid_hypothesis: We doubt that a man in the Navy stands on a boat in the cool air.
invalid_hypothesis: It is certain that a man in the Navy stands on a boat in the cool air.
hypothesis_assertion: A man in the Navy stands on a boat in the cool air.