context: It is probably the case that Lily is white. It is likely that Brian is a swan. Chances are slight that Bernhard is a lion. It is highly unlikely that if Bernhard is a lion, or Lily is white, then John went to the garden. Chances are about even that if Bernhard is a lion, or Lily is white, then Emily is a sheep. There is a better than even chance that if Lily is white, and Brian is a swan, then Mary got the milk.
hypothesis: It is highly unlikely that john went to the garden, and Lily is white.
valid_hypothesis: It is highly unlikely that john went to the garden, and Lily is white.
invalid_hypothesis: It is likely that john went to the garden, and Lily is white.
hypothesis_assertion: John went to the garden, and Lily is white.