Anchor: A snowboarder glides through the air.
Entailed: A person is snowboarding.
Contradiction: A snowboarder is not moving.
Contradiction: Tony Hawk is landing a 1080 on a vert ramp.
Contradiction: The snowboarder is eating lunch and waiting for his turn down the hill.
Contradiction: A snowboarder is sitting on his couch eating food.
Contradiction: There is a brick building underneath the snowboarder.