context: There is little chance that Sandra left the milk. It is probable that Julius is a swan. It is improbable that Lily is a lion. It is probably the case that if Sandra left the milk, and Lily is a lion, then Brian is white. Chances are about even that if Lily is a lion, or Sandra left the milk, then John went to the garden. Chances are slight that if either Julius is a swan, or Lily is a lion, then Greg is green.
hypothesis: It is impossible that greg is green, and Brian is white.
valid_hypothesis: It is impossible that greg is green, and Brian is white.
invalid_hypothesis: It is almost certain that greg is green, and Brian is white.
hypothesis_assertion: Greg is green, and Brian is white.