context: It is certain that Sandra took the apple. It is impossible that Brian is green. We doubt that Julius is a lion.
hypothesis: It is impossible that julius is a lion, and Brian is green.
valid_hypothesis: It is impossible that julius is a lion, and Brian is green.
invalid_hypothesis: Chances are about even that julius is a lion, and Brian is green.
hypothesis_assertion: Julius is a lion, and Brian is green.