context: It is certain that John left the apple. It is almost certain that Lily is white. It is certain that Brian is a swan. It is impossible that if Lily is white, and John left the apple, then Julius is a frog. It is probably not the case that if John left the apple, or Brian is a swan, then Mary went to the garden. There is a better than even chance that if Brian is a swan, and John left the apple, then Yann is tired.
hypothesis: Chances are about even that either Yann is tired, or Brian is a swan.
valid_hypothesis: Chances are about even that either Yann is tired, or Brian is a swan.
invalid_hypothesis: It is almost certain that either Yann is tired, or Brian is a swan.
hypothesis_assertion: Either Yann is tired, or Brian is a swan.