premise: A man in a black shirt and black jeans and a little boy are taking a look inside a green truck's engine while it is parked in a grass field with a gas tank in front of it. hypothesis: A couple of guys are drinking beers, watching TV.
contradiction: The subject cannot be a man and a couple of guys at the same time. Also, the subject(s) cannot be taking a look inside a truck's engine and drinking beers, watching TV at the same time.