Anchor: As to the sleeping powders, I knew by this." He suddenly produced a small cardboard box, such as chemists use for powders. 
Entailed: He knew about the sleeping powder because of the chemists' box.
Contradiction: He didn't know what the box was used for.
Contradiction: two people are playing hopscotch in the park
Contradiction: We have a vision of what the poet laureate is like.
Contradiction: It is cloudy.
Contradiction: A person is hiking a mountain with a shirt on.