Anchor: Some of the slaves were able to gain freedom in return for special services rendered.
Entailed: Some slaves were freed if they offered their services.
Contradiction: No slaves gained freedom.
Contradiction: You cannot visit the grounds until you have viewed all the artwork.
Contradiction:  A woman with a computer.
Contradiction: Several drivers yell at each other at a crowded red light
Contradiction: The cumulative total is good for estimating the amount of limestone.