Anchor: The teenage boy is dunking a basketball in a hoop.
Entailed: Boys play basketball.
Contradiction: The boy is dunking a hockey puck.
Contradiction: They are in deep trouble.
Contradiction: A man is swimming in a pool on an enclosed screened porch.
Contradiction: A swimmer, in a Olympic sized pool, is not dragging a foam circle
Contradiction: A man is riding a bike.