context: It is unlikely that Jessica is a mouse. It is probably the case that Lily is a rhino. There is a very good chance that Fred is in the school. There is almost no chance that if Fred is in the school, or Lily is a rhino, then Brian is yellow. We doubt that if either Lily is a rhino, or Fred is in the school, then John picked up the apple. There is a better than even chance that if Fred is in the school, and Lily is a rhino, then Julius is a lion.
hypothesis: It is likely that either Lily is a rhino, or Brian is yellow.
valid_hypothesis: It is likely that either Lily is a rhino, or Brian is yellow.
invalid_hypothesis: Chances are slight that either Lily is a rhino, or Brian is yellow.
hypothesis_assertion: Either Lily is a rhino, or Brian is yellow.