context: It is certain that Winona is a mouse. Chances are about even that Sandra took the apple. There is little chance that Mary went to the garden. It is probably not the case that if Mary went to the garden, and Winona is a mouse, then Bernhard is yellow. It is probable that if Sandra took the apple, and Winona is a mouse, then Julius is a lion. It is highly unlikely that if Sandra took the apple, or Winona is a mouse, then Greg is a swan.
hypothesis: It is impossible that sandra took the apple, or Greg is a swan.
valid_hypothesis: Chances are about even that sandra took the apple, or Greg is a swan.
invalid_hypothesis: It is impossible that sandra took the apple, or Greg is a swan.
hypothesis_assertion: Sandra took the apple, or Greg is a swan.