Anchor: Then, when the groups learned of one another's existence, the boys immediately drew lines in the sand.
Entailed: The group learned that the other existed and started a divide. 
Contradiction: The groups learned to work together. 
Contradiction: A man walks his bike in a black shirt
Contradiction: A person engaged in movement.
Contradiction: There is a cattle ranch on the east side of the island.
Contradiction: The Board planned to make sure that regular reporting of significant areas would be enforced.