Anchor: Brodkey is not obliged to be a poster boy for AIDS.
Entailed: Brodkey doesn't have to be the poster boy for AIDS
Contradiction: It's necessary that Brodkey is the poster boy for AIDS.
Contradiction: You can find the sausage needed for the dish at any store in town.
Contradiction: There is a group of people in an orchestra.
Contradiction: The cat was playing.
Contradiction: The American Medical Association Journal concerns medicine.