context: It is unlikely that Sandra left the milk. It is probably the case that Greg is a frog. We believe that Bernhard is white. Chances are slight that if Sandra left the milk, and Greg is a frog, then Mary dropped the apple. It is unlikely that if either Sandra left the milk, or Bernhard is white, then Lily is a swan. It is impossible that if Greg is a frog, and Bernhard is white, then John went to the garden.
hypothesis: There is a better than even chance that either Lily is a swan, or Greg is a frog.
valid_hypothesis: There is a better than even chance that either Lily is a swan, or Greg is a frog.
invalid_hypothesis: It is impossible that either Lily is a swan, or Greg is a frog.
hypothesis_assertion: Either Lily is a swan, or Greg is a frog.