Anchor: A surfer dressed in black catches a huge wave and starts riding on the descent.
Entailed: Someone is surfing.
Contradiction: A man is waiting to get on the bus.
Contradiction: An old man is rocking in a chair on a deck.
Contradiction: My wife is pregnant, so walking is good exercise for her.
Contradiction: The people are stacking bricks
Contradiction: Two people talk on cellphones outdoors.