Anchor: The helmeted boy is doing a stunt on a skateboard.
Entailed: A skateboarder in protective gear is doing tricks.
Contradiction: A boy is riding his bike.
Contradiction: Well, lets not do anything.
Contradiction: The white guy holding an instrument and wearing jeans.
Contradiction: There is no way to establish causality in cases like these.
Contradiction: We don't have all of our flower bulbs planted.