Anchor: In the dark of night, their aim must be true.
Entailed: In the shadows casted by the dark moon, their aim must be precise, or they shall fail.
Contradiction: They can aim almost perfectly in the dark, but not the daylight. 
Contradiction: a group of people are in a brick building
Contradiction: There is a man in the library.
Contradiction: A dog is staring at the hole he just dug.
Contradiction: A woman is wearing a purse.