Anchor: A boy sits alone at the bottom of a stone stairway.
Entailed: There is only one boy at the bottom of the stairway.
Contradiction: Four boys sit together at the bottom of the stone stairway.
Contradiction: Boy Scouts are camping in the dry desert.
Contradiction: There are at least two cars.
Contradiction: He did nothing for Hong Kong but make it weak and poverty stricken. 
Contradiction: A man is outside.