context: It is probably the case that Fred left the football. There is little chance that Greg is a swan. It is almost certain that Bernhard is yellow. There is a better than even chance that if Greg is a swan, and Bernhard is yellow, then Brian is a rhino. There is a very good chance that if Bernhard is yellow, or Greg is a swan, then Mary put down the milk. Chances are about even that if Bernhard is yellow, or Fred left the football, then Julius is white.
hypothesis: We believe that greg is a swan, or Fred left the football.
valid_hypothesis: We believe that greg is a swan, or Fred left the football.
invalid_hypothesis: It is improbable that greg is a swan, or Fred left the football.
hypothesis_assertion: Greg is a swan, or Fred left the football.