Anchor: It is worthwhile to rent a car so you can go at your own pace.
Entailed: It's worth being able to go at a pace you prefer.
Contradiction: It's not worth renting a car, you'll only want to move at a slow pace.
Contradiction: Children are playing on the playground unsupervised.
Contradiction: Advertising mailers are delivered by the Postal Service.
Contradiction: I enjoy going out by myself. 
Contradiction: The crowd watched the basketball players on the court.