Anchor: a bmx rider launches off a quarterpipe.
Entailed: A bike rider is on the quarterpipe.
Contradiction: The bike rider is riding in the park.
Contradiction: The person is on the toilet inside.
Contradiction: No doctor would tell you differently. 
Contradiction: She didn't say anything, just smiled.
Contradiction: One edition of the Benefits and Costs of the Clean Air Act applies to the time between 1970 and 1990.