context: It is impossible that Mary went to the kitchen. It is impossible that Brian is a frog. It is impossible that John put down the apple. It is certain that if Mary went to the kitchen, and John put down the apple, then Sandra grabbed the milk. It is improbable that if Brian is a frog, or John put down the apple, then Greg is yellow. It is improbable that if Brian is a frog, and John put down the apple, then Bernhard is gray.
hypothesis: It is certain that greg is yellow, and Bernhard is gray.
valid_hypothesis: It is impossible that greg is yellow, and Bernhard is gray.
invalid_hypothesis: It is certain that greg is yellow, and Bernhard is gray.
hypothesis_assertion: Greg is yellow, and Bernhard is gray.