context: It is highly likely that Julius is white. There is little chance that Sandra took the milk. We doubt that John picked up the apple. It is highly unlikely that if John picked up the apple, or Julius is white, then Mary moved to the garden. There is a better than even chance that if Julius is white, or John picked up the apple, then Greg is a swan. There is a better than even chance that if Sandra took the milk, or John picked up the apple, then Brian is gray.
hypothesis: It is certain that greg is a swan, and Brian is gray.
valid_hypothesis: It is improbable that greg is a swan, and Brian is gray.
invalid_hypothesis: It is certain that greg is a swan, and Brian is gray.
hypothesis_assertion: Greg is a swan, and Brian is gray.