premise: The backs of a woman and her dog as they walk away from the camera with the dog on a red leash and her in a green tank top. hypothesis: A man walks his dog with a black leash.
contradiction: It is either a man or a woman. The leash is either red or black.|contradiction: A man is not a woman.  A black leash is not a red leash.|contradiction: The subject is either a man or a woman.