context: Chances are about even that Lily is yellow. Chances are about even that Brian is a swan. It is probable that Bill dropped the milk. There is little chance that if Brian is a swan, or Bill dropped the milk, then Greg is green. It is probably not the case that if Brian is a swan, or Bill dropped the milk, then Mary went to the kitchen. There is a very good chance that if Brian is a swan, or Lily is yellow, then Sandra left the apple.
hypothesis: There is a better than even chance that either Greg is green, or Bill dropped the milk.
valid_hypothesis: There is a better than even chance that either Greg is green, or Bill dropped the milk.
invalid_hypothesis: It is highly unlikely that either Greg is green, or Bill dropped the milk.
hypothesis_assertion: Either Greg is green, or Bill dropped the milk.