context: People are pulling a big green tractor.
hypothesis: It is probable that the tractor got stuck and the people are pulling it out of the mud.
valid_hypothesis: It is probable that the tractor got stuck and the people are pulling it out of the mud.
invalid_hypothesis: There is little chance that the tractor got stuck and the people are pulling it out of the mud.
hypothesis_assertion: The tractor got stuck and the people are pulling it out of the mud.