Anchor: Dust rolled in a cloud with two or three riders at its center.
Entailed: There were two or three riders at the center when dust rolled.
Contradiction: Dust rolled in and there was only one man in the center.
Contradiction: Two men are bowling.
Contradiction: Nothing has happened.
Contradiction: The capitalists are all non-smokers and have no cigars.
Contradiction: A man at a desk