context: It is highly unlikely that Greg is a swan. It is impossible that John picked up the apple. There is a better than even chance that Julius is a rhino. It is likely that if John picked up the apple, and Greg is a swan, then Brian is gray. It is unlikely that if Julius is a rhino, or John picked up the apple, then Sandra got the football. Chances are about even that if either Julius is a rhino, or John picked up the apple, then Mary went to the office.
hypothesis: It is impossible that either Julius is a rhino, or Sandra got the football.
valid_hypothesis: Chances are about even that either Julius is a rhino, or Sandra got the football.
invalid_hypothesis: It is impossible that either Julius is a rhino, or Sandra got the football.
hypothesis_assertion: Either Julius is a rhino, or Sandra got the football.