context: It is improbable that Sandra took the football. Chances are slight that Greg is a swan. It is impossible that Bernhard is gray. There is a very good chance that if either Greg is a swan, or Sandra took the football, then Winona is a mouse. It is probably not the case that if Greg is a swan, and Sandra took the football, then Brian is yellow. Chances are slight that if either Greg is a swan, or Sandra took the football, then Lily is a lion.
hypothesis: It is impossible that bernhard is gray, and Sandra took the football.
valid_hypothesis: It is impossible that bernhard is gray, and Sandra took the football.
invalid_hypothesis: It is certain that bernhard is gray, and Sandra took the football.
hypothesis_assertion: Bernhard is gray, and Sandra took the football.