context: It is improbable that Brian is a swan. Chances are about even that Lily is a rhino. It is likely that Emily is a mouse. It is highly unlikely that if Brian is a swan, or Lily is a rhino, then Sandra left the apple. Chances are about even that if Emily is a mouse, and Brian is a swan, then John went to the garden. There is a better than even chance that if Lily is a rhino, or Emily is a mouse, then Greg is a frog.
hypothesis: It is improbable that either Brian is a swan, or Sandra left the apple.
valid_hypothesis: It is improbable that either Brian is a swan, or Sandra left the apple.
invalid_hypothesis: There is a very good chance that either Brian is a swan, or Sandra left the apple.
hypothesis_assertion: Either Brian is a swan, or Sandra left the apple.