premise: Two men in black jackets sit on a white bench at night on a cobbled courtyard. hypothesis: Two men in white jackets stand at night on black pavement.
contradiction: Black and white are different colors, so the jackets cannot be black and white at the same time. One cannot sit and stand simultaneously. Cobbled implies a different kind of road than pavement. Pavement is smooth and one material and cobbled is bumpy and comprised of lots of different stones.