context: We doubt that Greg is a swan. It is probably not the case that Brian is a frog. It is improbable that Bill went to the hallway.
hypothesis: It is highly unlikely that greg is a swan, and Brian is a frog.
valid_hypothesis: It is highly unlikely that greg is a swan, and Brian is a frog.
invalid_hypothesis: Chances are about even that greg is a swan, and Brian is a frog.
hypothesis_assertion: Greg is a swan, and Brian is a frog.