Anchor: Most Federal civilian employees hired before 1984 are not covered by Social Security.
Entailed: A number of older federal employees are not covered.
Contradiction: All the civilian employees from before 1984 have social security.
Contradiction: The person is riding a horse.
Contradiction: We do not have enough evidence to draw the conclusion that he lived here. 
Contradiction: People picket in the streets
Contradiction: A person is cutting down tall tree by machine.