Anchor: Important also is that if the improved service is not feasible, the mailer could decide to use an alternative to the postal system.
Entailed: The mailer could use an alternative to the postal system if the improved service isn't feasible.
Contradiction: The mailer has to use the postal system.
Contradiction: The men are playing football with the police officer at a field downtown.
Contradiction: A man is not wearing a shirt.
Contradiction: The girl is holding a live cat.
Contradiction: I like Penn State because both my parents went there