context: There is a better than even chance that Greg is a swan. It is impossible that Julius is yellow. It is improbable that Bernhard is a rhino.
hypothesis: It is impossible that greg is a swan, and Julius is yellow.
valid_hypothesis: It is impossible that greg is a swan, and Julius is yellow.
invalid_hypothesis: It is certain that greg is a swan, and Julius is yellow.
hypothesis_assertion: Greg is a swan, and Julius is yellow.