context: It is certain that Sandra took the apple. Chances are about even that Brian is a rhino. It is highly unlikely that John got the football. Chances are about even that if Sandra took the apple, or John got the football, then Lily is a swan. It is unlikely that if Brian is a rhino, or John got the football, then Julius is yellow. It is improbable that if John got the football, and Sandra took the apple, then Bill moved to the garden.
hypothesis: There is almost no chance that either Lily is a swan, or John got the football.
valid_hypothesis: Chances are about even that either Lily is a swan, or John got the football.
invalid_hypothesis: There is almost no chance that either Lily is a swan, or John got the football.
hypothesis_assertion: Either Lily is a swan, or John got the football.