context: We believe that Brian is a lion. We doubt that Sandra got the apple. There is a very good chance that Greg is a frog. Chances are slight that if Greg is a frog, or Sandra got the apple, then Lily is a swan. It is unlikely that if Brian is a lion, and Greg is a frog, then John picked up the milk. There is little chance that if Greg is a frog, or Sandra got the apple, then Fred left the football.
hypothesis: There is almost no chance that sandra got the apple, and Fred left the football.
valid_hypothesis: There is almost no chance that sandra got the apple, and Fred left the football.
invalid_hypothesis: Chances are about even that sandra got the apple, and Fred left the football.
hypothesis_assertion: Sandra got the apple, and Fred left the football.