context: It is certain that Greg is a swan. It is likely that John went to the office. It is unlikely that Julius is a lion.
hypothesis: It is certain that julius is a lion, or Greg is a swan.
valid_hypothesis: It is certain that julius is a lion, or Greg is a swan.
invalid_hypothesis: Chances are about even that julius is a lion, or Greg is a swan.
hypothesis_assertion: Julius is a lion, or Greg is a swan.