context: It is highly likely that John left the apple. It is highly unlikely that Sandra dropped the milk. Chances are slight that Julius is white. Chances are slight that if Sandra dropped the milk, and John left the apple, then Mary went to the kitchen. It is impossible that if either Sandra dropped the milk, or Julius is white, then Bernhard is a rhino. There is almost no chance that if either John left the apple, or Sandra dropped the milk, then Brian is a swan.
hypothesis: We doubt that either Mary went to the kitchen, or John left the apple.
valid_hypothesis: It is highly likely that either Mary went to the kitchen, or John left the apple.
invalid_hypothesis: We doubt that either Mary went to the kitchen, or John left the apple.
hypothesis_assertion: Either Mary went to the kitchen, or John left the apple.