context: It is certain that Bernhard is a swan. Chances are slight that Brian is a lion. It is unlikely that Mary took the football.
hypothesis: We believe that either Mary took the football, or Brian is a lion.
valid_hypothesis: It is probably not the case that either Mary took the football, or Brian is a lion.
invalid_hypothesis: We believe that either Mary took the football, or Brian is a lion.
hypothesis_assertion: Either Mary took the football, or Brian is a lion.