context: It is probably not the case that Sandra left the milk. Chances are about even that Mary went to the garden. Chances are about even that Emily is a mouse.
hypothesis: Chances are about even that either Emily is a mouse, or Sandra left the milk.
valid_hypothesis: Chances are about even that either Emily is a mouse, or Sandra left the milk.
invalid_hypothesis: It is impossible that either Emily is a mouse, or Sandra left the milk.
hypothesis_assertion: Either Emily is a mouse, or Sandra left the milk.