Anchor: The people farmed and fished; on the dawning of the Bronze Age in 2700 b.c. , they began to work with metals.
Entailed: The people farmed until they learned to use metals.
Contradiction: The people farmed until they learned to use water.
Contradiction: The diver is sleeping.
Contradiction: Tuppence was being coerced into sleeping. 
Contradiction: Two men are eating at a restaurant
Contradiction: A skateboarder rides.