Anchor: We had just put away the last tea-spoon when a knock came at the door. 
Entailed: there was a knock on the door.
Contradiction: We put away the silverware and went to bed.
Contradiction: There's a wall which we can use as a natural choke point.
Contradiction: The man enjoys his beverage.
Contradiction: Knowledge of the web address is not necessary.
Contradiction: The boy is smiling while people watch him.