Anchor: A man rides a surfboard over a wave, the nose of the board pointing downward.
Entailed: A man is surfing outside.
Contradiction: a man is sitting on his surfboard waiting for some waves.
Contradiction: A man riding his bike as large waves come down.
Contradiction: All the water in the world has frozen.
Contradiction: The man is snowboarding down a hill.
Contradiction: A man fell off his surfboard while surfing.