context: It is impossible that Lily is gray. Chances are about even that John left the football. We doubt that Greg is green. It is highly unlikely that if Lily is gray, and Greg is green, then Mary went to the bedroom. Chances are slight that if either Greg is green, or Lily is gray, then Brian is a frog. It is highly unlikely that if either Greg is green, or John left the football, then Julius is a rhino.
hypothesis: It is impossible that julius is a rhino, and Lily is gray.
valid_hypothesis: It is impossible that julius is a rhino, and Lily is gray.
invalid_hypothesis: It is certain that julius is a rhino, and Lily is gray.
hypothesis_assertion: Julius is a rhino, and Lily is gray.