premise: People in front of waterfront, 3 people are sitting down facing each other as a young boy runs and 2 people walk towards the water. hypothesis: 3 people are seated with their backs against each other.
contradiction: the people cannot be  facing each other and also have their backs against each other.|contradiction: They are facing each other, so can not have their backs against each other.|contradiction: The people cannot be sitting facing each other and with the backs against each other at the same time.