context: It is highly unlikely that Brian is a rhino. We doubt that Greg is yellow. There is almost no chance that Bill got the milk there. It is probably the case that if Brian is a rhino, and Bill got the milk there, then Jeff went to the kitchen. There is almost no chance that if either Bill got the milk there, or Greg is yellow, then John dropped the apple. It is unlikely that if Bill got the milk there, and Brian is a rhino, then Julius is a swan.
hypothesis: It is impossible that jeff went to the kitchen, and Bill got the milk there.
valid_hypothesis: It is impossible that jeff went to the kitchen, and Bill got the milk there.
invalid_hypothesis: It is almost certain that jeff went to the kitchen, and Bill got the milk there.
hypothesis_assertion: Jeff went to the kitchen, and Bill got the milk there.