Anchor: He reached for the arm around his neck and began breaking it free from its stranglehold.
Entailed: He pulled the arm off of his neck. 
Contradiction: He allowed the arm to continue choking him. 
Contradiction: The workers are swimming.
Contradiction: Construction workers are talking to a coworker.
Contradiction: two people are on a dock
Contradiction: This produces cost functions for each of the postal activities.