Anchor: Three firemen are conversing next to a firetruck.
Entailed: There are firemen having a conversation beside their truck.
Contradiction: the firemen are fighting a fire.
Contradiction: Three firemen are working with a patient that has been badly injured.
Contradiction: Several police officers stand next to  a firetruck.
Contradiction: There are three police officers eating dinner.
Contradiction: Three police officers are conversing near a squad car.