context: Chances are about even that John went to the kitchen. We doubt that Daniel took the football. There is almost no chance that Bernhard is a swan. It is likely that if John went to the kitchen, or Daniel took the football, then Fred is in the office. It is likely that if Daniel took the football, or Bernhard is a swan, then Greg is a frog. It is unlikely that if either Bernhard is a swan, or Daniel took the football, then Brian is gray.
hypothesis: It is certain that daniel took the football, and Brian is gray.
valid_hypothesis: It is highly unlikely that daniel took the football, and Brian is gray.
invalid_hypothesis: It is certain that daniel took the football, and Brian is gray.
hypothesis_assertion: Daniel took the football, and Brian is gray.