context: It is impossible that Greg is a swan. It is certain that Mary went to the garden. Chances are about even that Sandra left the football.
hypothesis: It is highly unlikely that either Greg is a swan, or Sandra left the football.
valid_hypothesis: Chances are about even that either Greg is a swan, or Sandra left the football.
invalid_hypothesis: It is highly unlikely that either Greg is a swan, or Sandra left the football.
hypothesis_assertion: Either Greg is a swan, or Sandra left the football.