context: It is certain that Fred went to the garden. There is a better than even chance that Mary left the apple. Chances are slight that Brian is a rhino. We believe that if either Fred went to the garden, or Brian is a rhino, then Julius is a swan. We doubt that if either Fred went to the garden, or Mary left the apple, then Bill dropped the milk. It is probable that if Mary left the apple, and Brian is a rhino, then Greg is a frog.
hypothesis: It is probably the case that either Bill dropped the milk, or Brian is a rhino.
valid_hypothesis: It is unlikely that either Bill dropped the milk, or Brian is a rhino.
invalid_hypothesis: It is probably the case that either Bill dropped the milk, or Brian is a rhino.
hypothesis_assertion: Either Bill dropped the milk, or Brian is a rhino.