Anchor: Two musicians are playing a duet one on a harp and the other on a violin.
Entailed: Two musicians are playing a duet.
Contradiction: Two musicians are swimming.
Contradiction: The Harem is open 24 hours a day.  
Contradiction: They spent 43,692 hours for all the collections.
Contradiction: Should people even be eating pork anymore given the salmonella scare?
Contradiction: You would want that to be the case.