context: Chances are about even that Sandra took the milk. There is almost no chance that Lily is a swan. It is improbable that Brian is yellow.
hypothesis: It is probably the case that brian is yellow, or Lily is a swan.
valid_hypothesis: It is improbable that brian is yellow, or Lily is a swan.
invalid_hypothesis: It is probably the case that brian is yellow, or Lily is a swan.
hypothesis_assertion: Brian is yellow, or Lily is a swan.