context: It is highly likely that Sandra grabbed the milk. There is little chance that Mary went to the kitchen. Chances are about even that Brian is a swan. We believe that if Mary went to the kitchen, or Brian is a swan, then Julius is a rhino. There is almost no chance that if either Sandra grabbed the milk, or Mary went to the kitchen, then John got the apple. It is highly unlikely that if either Mary went to the kitchen, or Brian is a swan, then Greg is gray.
hypothesis: It is highly unlikely that either Mary went to the kitchen, or Brian is a swan.
valid_hypothesis: Chances are about even that either Mary went to the kitchen, or Brian is a swan.
invalid_hypothesis: It is highly unlikely that either Mary went to the kitchen, or Brian is a swan.
hypothesis_assertion: Either Mary went to the kitchen, or Brian is a swan.