context: It is almost certain that Daniel left the milk. It is improbable that Fred moved to the office. There is a better than even chance that Greg is a lion. It is likely that if Daniel left the milk, or Greg is a lion, then Sandra took the football. It is probably the case that if either Fred moved to the office, or Daniel left the milk, then Brian is yellow. There is little chance that if Greg is a lion, and Daniel left the milk, then Mary went to the hallway.
hypothesis: It is highly unlikely that either Greg is a lion, or Sandra took the football.
valid_hypothesis: Chances are about even that either Greg is a lion, or Sandra took the football.
invalid_hypothesis: It is highly unlikely that either Greg is a lion, or Sandra took the football.
hypothesis_assertion: Either Greg is a lion, or Sandra took the football.