context: Chances are about even that John went to the garden. There is almost no chance that Julius is a swan. It is likely that Gertrude is a cat. We doubt that if John went to the garden, and Julius is a swan, then Brian is a frog. There is almost no chance that if John went to the garden, or Gertrude is a cat, then Greg is green. It is improbable that if either Julius is a swan, or John went to the garden, then Daniel left the milk.
hypothesis: It is probable that gertrude is a cat, and Brian is a frog.
valid_hypothesis: It is impossible that gertrude is a cat, and Brian is a frog.
invalid_hypothesis: It is probable that gertrude is a cat, and Brian is a frog.
hypothesis_assertion: Gertrude is a cat, and Brian is a frog.