context: Chances are slight that Greg is green. It is likely that Bernhard is a lion. Chances are about even that John picked up the milk. We believe that if either Bernhard is a lion, or Greg is green, then Julius is a frog. It is likely that if either John picked up the milk, or Greg is green, then Brian is a rhino. It is highly likely that if John picked up the milk, or Greg is green, then Mary dropped the apple.
hypothesis: It is impossible that either Julius is a frog, or Brian is a rhino.
valid_hypothesis: Chances are about even that either Julius is a frog, or Brian is a rhino.
invalid_hypothesis: It is impossible that either Julius is a frog, or Brian is a rhino.
hypothesis_assertion: Either Julius is a frog, or Brian is a rhino.