premise: Police are setting up a barricade due to a fire. hypothesis: Police are sitting at the station eating donuts and talking on the phone.
contradiction: Police are either setting up a barricade or sitting at the station eating donuts and talking on the phone.|contradiction: The police cannot set up a barricade and sit and eat donuts at the station at the same time.|contradiction: police would be either setting up a barricade or sitting in the station.