context: Chances are slight that Brian is a swan. It is probably the case that John picked up the apple. It is improbable that Gertrude is a cat. It is highly unlikely that if either John picked up the apple, or Gertrude is a cat, then Greg is white. It is highly likely that if Brian is a swan, or John picked up the apple, then Lily is a rhino. It is unlikely that if Brian is a swan, and Gertrude is a cat, then Winona is a mouse.
hypothesis: It is highly unlikely that either Winona is a mouse, or Lily is a rhino.
valid_hypothesis: It is probably the case that either Winona is a mouse, or Lily is a rhino.
invalid_hypothesis: It is highly unlikely that either Winona is a mouse, or Lily is a rhino.
hypothesis_assertion: Either Winona is a mouse, or Lily is a rhino.