context: It is impossible that Greg is white. It is probably not the case that Sandra grabbed the milk. Chances are about even that Brian is a swan.
hypothesis: We believe that either Sandra grabbed the milk, or Greg is white.
valid_hypothesis: It is probably not the case that either Sandra grabbed the milk, or Greg is white.
invalid_hypothesis: We believe that either Sandra grabbed the milk, or Greg is white.
hypothesis_assertion: Either Sandra grabbed the milk, or Greg is white.