context: It is likely that Sandra put down the milk. There is a very good chance that Julius is a lion. Chances are about even that Bernhard is a swan. It is highly likely that if either Sandra put down the milk, or Bernhard is a swan, then John left the football. It is improbable that if Bernhard is a swan, and Julius is a lion, then Brian is yellow. It is improbable that if either Julius is a lion, or Bernhard is a swan, then Mary went to the garden.
hypothesis: It is improbable that either Brian is yellow, or Mary went to the garden.
valid_hypothesis: It is improbable that either Brian is yellow, or Mary went to the garden.
invalid_hypothesis: It is probably the case that either Brian is yellow, or Mary went to the garden.
hypothesis_assertion: Either Brian is yellow, or Mary went to the garden.