context: It is probably not the case that Greg is a rhino. Chances are about even that John got the apple. There is a very good chance that Brian is a swan. It is unlikely that if John got the apple, and Greg is a rhino, then Julius is a frog. It is impossible that if either Brian is a swan, or John got the apple, then Lily is gray. It is certain that if Brian is a swan, or Greg is a rhino, then Fred is in the office.
hypothesis: Chances are about even that either Lily is gray, or John got the apple.
valid_hypothesis: Chances are about even that either Lily is gray, or John got the apple.
invalid_hypothesis: It is almost certain that either Lily is gray, or John got the apple.
hypothesis_assertion: Either Lily is gray, or John got the apple.