Anchor: a lady is wearing all black with a whistle in the middle of rollerskaters.
Entailed: SHe is the referee in roller derby match.
Contradiction: A woman is in the middle of some basketball players.
Contradiction: She is refereeing a football game.
Contradiction: A lady is ice skating
Contradiction: A referee watches the snow skiiers.
Contradiction: A child in a soggy diaper.