context: It is unlikely that Lily is white. It is improbable that John took the football. It is likely that Julius is a lion. There is little chance that if Lily is white, and Julius is a lion, then Fred went to the cinema. There is a very good chance that if either Julius is a lion, or Lily is white, then Brian is a frog. It is probably not the case that if Julius is a lion, or John took the football, then Greg is yellow.
hypothesis: Chances are about even that either Brian is a frog, or John took the football.
valid_hypothesis: Chances are about even that either Brian is a frog, or John took the football.
invalid_hypothesis: It is certain that either Brian is a frog, or John took the football.
hypothesis_assertion: Either Brian is a frog, or John took the football.