context: We believe that John took the apple. Chances are slight that Daniel got the milk. It is certain that Greg is a swan. We doubt that if either Greg is a swan, or John took the apple, then Julius is white. It is highly unlikely that if John took the apple, and Greg is a swan, then Jeff went to the garden. It is unlikely that if Greg is a swan, and Daniel got the milk, then Mary dropped the milk.
hypothesis: There is almost no chance that mary dropped the milk, and John took the apple.
valid_hypothesis: There is almost no chance that mary dropped the milk, and John took the apple.
invalid_hypothesis: There is a very good chance that mary dropped the milk, and John took the apple.
hypothesis_assertion: Mary dropped the milk, and John took the apple.