context: It is almost certain that Julius is a frog. We believe that Bill went to the bedroom. It is certain that Winona is a mouse. Chances are about even that if Winona is a mouse, or Julius is a frog, then Jeff discarded the apple. Chances are slight that if either Winona is a mouse, or Julius is a frog, then Sandra took the milk. It is probably the case that if either Bill went to the bedroom, or Julius is a frog, then Brian is a rhino.
hypothesis: We doubt that sandra took the milk, or Brian is a rhino.
valid_hypothesis: We doubt that sandra took the milk, or Brian is a rhino.
invalid_hypothesis: It is probably the case that sandra took the milk, or Brian is a rhino.
hypothesis_assertion: Sandra took the milk, or Brian is a rhino.