premise: A man in a red shirt is walking in the grass near a sidewalk and empty street. hypothesis: the man is sitting in his house.
contradiction: Walking means that the a person is supporting themselves on their two legs and two feet and and moving in some direction, where as if a person is sitting they would be stationary and would be resting on their rear-end. Being on a street implies that the man is outside, which contradicts him being inside his house.