Anchor: A guy on a skateboard does a trick on a ramp while others watch on the other side of the ramp.
Entailed: A skateboarder does tricks while people watch.
Contradiction: A guy on a surfboard rides a wave at a competition.
Contradiction: A man skateboards down a sidewalk.
Contradiction: A man rollerblades down a steep hill, while others watch.
Contradiction: A skateboarder knocks over a woman while doing tricks on a sidewalk.
Contradiction: The skateboarder is alone at the park.