context: We doubt that Brian is white. There is almost no chance that John dropped the milk. Chances are slight that Julius is a lion.
hypothesis: It is impossible that julius is a lion, and John dropped the milk.
valid_hypothesis: It is impossible that julius is a lion, and John dropped the milk.
invalid_hypothesis: There is a better than even chance that julius is a lion, and John dropped the milk.
hypothesis_assertion: Julius is a lion, and John dropped the milk.