context: It is probably not the case that John dropped the apple. There is a better than even chance that Yann got the milk there. It is almost certain that Julius is a frog. It is impossible that if Julius is a frog, or John dropped the apple, then Fred went to the hallway. Chances are about even that if Julius is a frog, or John dropped the apple, then Sandra left the football. It is certain that if Yann got the milk there, and Julius is a frog, then Brian is a frog.
hypothesis: It is certain that either Fred went to the hallway, or Sandra left the football.
valid_hypothesis: Chances are about even that either Fred went to the hallway, or Sandra left the football.
invalid_hypothesis: It is certain that either Fred went to the hallway, or Sandra left the football.
hypothesis_assertion: Either Fred went to the hallway, or Sandra left the football.