premise: A man dressed in a surfing shirt and blue and white shorts skillfully guides his yellow board with its multicolored sail over the crest of an ocean wave, flipping over in the process. hypothesis: a man sleeps in bed.
contradiction: A sleeping man doesn't guide a board.|contradiction: The man cannot be sleeping if he is guiding his yellow board.  The man cannot be at the ocean if he is in bed.|contradiction: A man who guides his board over the crest of an ocean wave, flipping over in the process cannot be sleeping in bed at the same time.