context: It is highly unlikely that Brian is white. We doubt that Julius is a swan. It is highly likely that John took the apple. There is a very good chance that if Julius is a swan, and John took the apple, then Bernhard is yellow. It is unlikely that if either John took the apple, or Brian is white, then Mary went to the office. Chances are about even that if either Julius is a swan, or John took the apple, then Lily is yellow.
hypothesis: We believe that brian is white, and John took the apple.
valid_hypothesis: It is highly unlikely that brian is white, and John took the apple.
invalid_hypothesis: We believe that brian is white, and John took the apple.
hypothesis_assertion: Brian is white, and John took the apple.