context: It is highly likely that Greg is a frog. It is unlikely that John dropped the apple. It is unlikely that Mary moved to the garden. There is little chance that if either John dropped the apple, or Mary moved to the garden, then Sandra grabbed the milk. Chances are about even that if Mary moved to the garden, or Greg is a frog, then Bernhard is a swan. We believe that if John dropped the apple, or Greg is a frog, then Brian is a lion.
hypothesis: It is probable that brian is a lion, and Sandra grabbed the milk.
valid_hypothesis: There is almost no chance that brian is a lion, and Sandra grabbed the milk.
invalid_hypothesis: It is probable that brian is a lion, and Sandra grabbed the milk.
hypothesis_assertion: Brian is a lion, and Sandra grabbed the milk.